Buzzword → answer (the vignette reflex)

• Microspherocytes (no central pallor) + Coombs-negative → hereditary spherocytosis (Coombs-negative separates it from AIHA; osmotic fragility ↑)
• Elliptical / oval red cells → hereditary elliptocytosis (the "milder cousin" of HS)
• Bite cells + Heinz bodies → G6PD deficiency (X-linked; triggers = fava beans, mothballs/naphthalene, oxidant drugs)
• Poikilocytosis + autohaemolysis NOT corrected by glucose → pyruvate kinase deficiency (raised 2,3-DPG → mild symptoms despite low Hb)
• HbH inclusion bodies ("golf-ball" cells) on reticulocyte prep → HbH disease (3-gene α-thal); Hb Barts / hydrops fetalis → 4-gene α deletion
• Sickle cells (target cells prominent in HbSC) → sickle cell disease
• Auer rods → AML (pathognomonic myeloblast; never ALL); MPO / Sudan Black + = myeloid lineage
• Gum hypertrophy / chloromas (oral lesions) → AML M4/M5 (monocytic)
• TdT+ (& PAS+) blasts, no Auer rods → ALL; mediastinal/thymic mass in an adolescent male → T-ALL (presents as lymphoma, airway emergency)
• Smudge / smear cells → CLL
• Aquagenic pruritus (itch after hot shower) → polycythaemia vera
• Teardrop cells + leucoerythroblastic film + massive spleen → primary myelofibrosis
• Reed-Sternberg "owl-eye" (bi/multinucleated) → Hodgkin; popcorn (L&H) cells → NLPHL; collagen bands + lacunar cells → nodular sclerosis (commonest HL)
• Pautrier microabscesses + cerebriform nuclei + epidermotropism → mycosis fungoides (signature triad); leukaemic spread = Sézary
• Tingible-body macrophages ("starry sky") → reactive node — absent in follicular lymphoma; gastric MALToma → H. pylori
• Rouleaux + punched-out lytic lesions / "pepper-pot" skull → myeloma (radio-isotope bone scan false-negative); Bence Jones protein = urinary free light chains
• Congo red → apple-green birefringence under polarised light → amyloid (pathognomonic); β-γ bridging (polyclonal, high IgA) → cirrhosis
• Pancytopenia + hypocellular ("empty") marrow → aplastic anaemia; "Fanconi thumbs" (absent/hypoplastic) → Fanconi anaemia
• Cytopenias + HYPERcellular marrow, ring sideroblasts / Pelger-Huët → MDS ("pre-leukaemia" → AML)
• Howell-Jolly bodies → hyposplenism / post-splenectomy; atypical lymphocytes (abundant cytoplasm) → infectious mononucleosis (EBV)

Genetics / translocations → disease → hook

MPN split: BCR-ABL⁺ = CML; BCR-ABL⁻ classic = PV/ET/PMF (non-classic = mastocytosis, chronic neutrophilic/eosinophilic leukaemia). Almost everything (PV, ET, PMF, MDS) can transform → AML.

Criteria / staging / scores at a glance

• Ann Arbor (lymphoma): I = one node region (or single extranodal, IE) → II = ≥2 regions same side of diaphragm → III = both sides → IV = disseminated extranodal (e.g. marrow). A = no symptoms; B = fever + drenching night sweats + weight loss >10% in 6 months; X (bulky) = >⅓ mediastinal widening OR nodal mass >10 cm; E = single contiguous extranodal site
• Rai (CLL): 0 = lymphocytosis only → 1 = + nodes → 2 = + organomegaly → 3 = + anaemia (Hb <11) → 4 = + thrombocytopenia (Plt <100k). Stages 3–4 = high risk
• Binet (CLL): A = Hb ≥10, Plt ≥100k, <3 areas; B = same bloods, ≥3 areas; C = Hb <10 and/or Plt <100k. (5 areas = neck, axilla, groin, spleen, liver; C ≈ Rai III/IV)
• Active myeloma = CRAB + SLiM. CRAB: C hypercalcaemia (>11 mg/dL or >1 above ULN), R renal (CrCl <40 mL/min or Cr >2 mg/dL), A anaemia (Hb <100 g/L or >20 below LLN), B ≥1 osteolytic bone lesion. SLiM: Sixty = clonal BM plasma cells ≥60%; Light chains = involved:uninvolved FLC ratio ≥100; MRI = >1 focal lesion
• MGUS vs smouldering vs active: MGUS = M-protein <30 g/L & plasma cells <10% & no CRAB; smouldering = >30 g/L & >10% & no CRAB; active = plasma cells ≥10% (or plasmacytoma) + CRAB/SLiM present
• ISS / R-ISS (myeloma): ISS = albumin + β2-microglobulin (tumour burden). R-ISS adds LDH + genetics: I = ISS I + normal LDH + no high-risk genetics (6–7 y); III = ISS III + (high LDH OR high-risk genetics) (<2–3 y). High-risk genetics = t(4;14), t(14;16), del(17p)
• FAB AML (M0–M7): M0 no maturation → M1 minimal → M2 with maturation → M3 = APL (DIC, ATRA) → M4 myelomonocytic → M5 monocytic (gum hypertrophy) → M6 erythroid → M7 megakaryoblastic
• IPSS (MDS prognosis): number of cytopenias + number of marrow blasts + cytogenetic abnormalities
• α-thalassaemia genotypes: −α/αα (1 gene) = silent carrier; −−/αα or −α/−α (2) = α-trait (microcytosis); −−/−α (3) = HbH disease (β₄ tetramers, haemolysis); −−/−− (4) = Hb Barts/hydrops (incompatible with life). α defects = deletions → MLPA/multiplex PCR
• β-thalassaemia genotypes: β/β⁺ or β/β⁰ = trait (minor); β⁰/β⁰ or β⁺/β⁺ = major. β defects = point mutations → β-globin sequencing; two carriers → 25% chance of a major child
• IDA vs β-thal trait: RBC count IDA <5.0 ×10⁶/µL (low) vs β-thal >5.0 (relatively high); RDW elevated IDA vs ≤14% β-thal; HbA2 normal/low IDA vs raised (>3.5%) β-thal
• Iron chelation (thalassaemia): deferoxamine (SC/IV, 30–60 mg/kg, poor compliance); deferasirox (oral OD, 20 mg/kg, hold if ferritin <500 µg/L); deferiprone (oral, cardiac, risk neutropenia/agranulocytosis → weekly CBC). Start after 10–20 transfusions OR ferritin ≥1000 µg/L OR age 3
• Amyloidosis classification: AL = paraproteinaemia/primary/myeloma; AA = chronic inflammation/infection or Familial Mediterranean Fever; ASc = senile/cardiac; PA = neuropathy. Dx = Congo red → apple-green birefringence
• Acute vs chronic leukaemia: acute = blasts (immature), sudden onset, all ages, mild–severe cytopenias, mild organomegaly; chronic = mature cells, insidious, adults, WBC increased, organomegaly prominent

Discriminators that decide questions

1. Micro + high RBC → β-thal trait; micro + low RBC → IDA (RBC is high in thal). β-thal trait also has RDW ≤14% and HbA2 >3.5%; IDA has elevated RDW and normal/low HbA2.
2. Low EPO + JAK2 → primary polycythaemia (PV); high EPO → secondary polycythaemia.
3. Reactive vs neoplastic node: reactive = polyclonal (CD3+/CD20+ mixed), tingible-body macrophages present; neoplastic = monoclonal (light-chain restriction). CD45(LCA)+ = lymphoma; CD45− node mass = metastasis. CD3+/CD20− = T-cell lymphoma; CD3−/CD20+ = B-cell lymphoma.
4. Auer rods AML vs TdT+ ALL: Auer rods + MPO/Sudan Black+ = AML; TdT+ & PAS+, no Auer rods = ALL (B-ALL = CD20+TdT, T-ALL = CD3+TdT).
5. Aplastic anaemia vs MDS (both cause cytopenias): aplastic = hypocellular "empty" marrow (fat-replaced); MDS = hypercellular / ineffective marrow with dysplasia → pre-leukaemia.
6. Sickle aplastic vs sequestration crisis (both = sudden severe anaemia): aplastic (parvovirus B19 kills erythroid precursors) → LOW reticulocytes; sequestration (organ pooling) → HIGH reticulocytes. And CD5+CD23+ B-cell = CLL; persistent lymphocytosis in a patient >60 = CLL until proven otherwise.

Buzzword → answer (the vignette reflex)

• Epsilon wave (small notch at end of QRS) → ARVC (pathognomonic; fibro-fatty replacement of RV free wall)
• Delta wave + short PR <120 ms + wide QRS >120 ms → WPW
• Beck's triad + pulsus paradoxus + electrical alternans → cardiac tamponade (pathognomonic combo)
• Widespread saddle-shaped (concave) ST elevation + PR depression, no reciprocal ST depression → acute pericarditis
• Pulsus parvus et tardus (small-volume, slow-rising carotid) → aortic stenosis
• Water-hammer / collapsing pulse + Corrigan's, Quincke's, De Musset's, Duroziez's → aortic regurgitation
• Loud S1 + opening snap + mid-diastolic rumble at apex + malar (mitral) flush → mitral stenosis (almost always rheumatic)
• Tearing/ripping chest pain maximal at onset + "cobweb" sign on TOE (100% specific for false lumen) → aortic dissection
• S1Q3T3 + new RBBB → PE (classic but uncommon)
• Osler's nodes / Janeway lesions / Roth spots / splinter haemorrhages + fever + new murmur → infective endocarditis
• Apical ballooning + unobstructed coronaries, older woman after stress → Tako-tsubo cardiomyopathy
• Voltage-mass mismatch (low ECG voltage + thickened walls) + speckled/ground-glass myocardium → cardiac amyloidosis
• Fibrinoid necrosis of arterioles + flea-bitten kidney + papilloedema → malignant HTN
• Asymmetric septal hypertrophy (ASH) + systolic anterior motion (SAM); murmur ↑ with Valsalva/standing → HCM

Murmur / heart sound → lesion

Criteria / staging / scores at a glance

Diagnostic criteria

• Modified Duke (IE): Major = +blood cultures/histology, echo vegetation. Definite = 2 major, or 1 major + 3 minor, or 5 minor; Possible = 1 major + 1–2 minor, or 3–4 minor.
• 2023 ESC IE: Definite = 2 major, 1 major + ≥3 minor, or 5 minor; Possible = 1 major + 1–2 minor, or 3–4 minor; else Rejected.
• Dutch Lipid Clinic (FH): Definite >8, Probable 6–8, Possible 3–5 (tendinous xanthomata 6 pts, arcus <45 yr 4 pts, LDL-C ≥325 = 8 pts, LDLR/ApoB/PCSK9 mutation 8 pts; one score per group).
• Task Force (ARVC): 5 categories — structural, tissue biopsy, ECG, Holter, family history.

Risk scores

• CHA₂DS₂-VA: C(HF)1, H(HTN)1, A₂(≥75)2, D(diabetes)1, S₂(prior stroke/TIA)2, V(vascular)1, A(65–74)1, Sc(female)1 → ≥2 OAC recommended, =1 consider, =0 none.
• HAS-BLED: 9 components (HTN SBP ≥160, abnormal renal, abnormal liver, stroke, bleeding, labile INR, elderly ≥65, drugs, alcohol) → score 0 ≈1%/yr, ≥3 >5%/yr (high) — modify factors, do NOT withhold OAC.
• ACS risk: GRACE (age, HR, SBP, creatinine, HF, arrest, ST deviation, troponin); HEART (History, EKG, Age, Risk factors, Troponin); TIMI.
• SCORE2 (40–69) / SCORE2-OP (≥70): 10-yr fatal + non-fatal CV events; ≥10% = high, 5–<10% = borderline.
• HCM SCD: ICD if ≥2 of — LVH >30 mm, FHx SCD <50 yr, NSVT, unexplained syncope, abnormal (flat/hypotensive) BP response to exercise; <2 → amiodarone.

Anatomical classifications

• Aortic dissection: Stanford A = ascending (= DeBakey I/II) → surgery; Stanford B = descending only (= DeBakey III) → medical. DeBakey I 60%, II 10–15%, III 25–30%.
• MI universal: Type 1 = plaque rupture + thrombus; Type 2 = supply–demand imbalance (2a vasospasm, 2b fixed atherosclerosis, 2c severe anaemia/hypotension).
• ACS: UA = troponin−, ST depression/T-changes or normal; NSTEMI = troponin+, no ST elevation; STEMI = troponin+ + ST elevation. NSTE-ACS = UA + NSTEMI.
• AF clinical: paroxysmal <7 days, persistent >7 days, longstanding persistent >1 year, permanent (agreed to stop rhythm control).
• Fredrickson: I chylomicrons; IIa LDL (= FH, commonest); IIb LDL+VLDL; III IDL; IV VLDL; V VLDL+chylomicrons.

Severity classifications

• NYHA: I no limitation; II slight (ordinary activity → symptoms); III marked (less-than-ordinary → symptoms); IV symptoms at rest.
• HF by LVEF: HFrEF ≤40%, HFmrEF 41–49%, HFpEF ≥50% (HFpEF/HFmrEF also need raised filling pressures).
• ACC/AHA stages: A at-risk → B pre-HF (structural/biomarker) → C symptomatic → D refractory. Maps: A→none, B→NYHA I, C→NYHA II–IV, D→NYHA IV (structural progression is one-way).
• HTN BP cutoffs: office non-elevated <120/70, elevated 120–139/70–89, HTN ≥140/90; ABPM 24-h ≥130/80, daytime ≥135/85, night ≥120/70; HBPM ≥135/85.
• HTN primary vs secondary: primary 90% (>40 yr, gradual), secondary 10% (<40 yr, abrupt, potentially curable).
• HTN benign vs malignant: benign = hyaline arteriolosclerosis; malignant = hyperplastic arteriolosclerosis ("onion-skinning") + fibrinoid necrosis + papilloedema + MAHA.
• Cardiomyopathies: HCM, DCM, RCM, ARVC, + other (LVNC, Tako-tsubo, peripartum, tachycardia-induced, obliterative/EMF).

ECG criteria

• Chamberlain's 10 rules = normal ECG (PR 120–200 ms, QRS <110 ms, aVR all-negative, R grows V1→V4, etc.).
• LBBB: QRS ≥120 ms, V1–V2 QS/rS, V5–V6/I monophasic R → cannot diagnose MI, ischaemia, enlargement, hemiblock.
• RBBB: QRS ≥120 ms, rsR' "rabbit ears" V1–V2, slurred S in I/V5/V6 → cannot diagnose ischaemia or enlargement (MI still diagnosable).
• LVH: Sokolow-Lyon S V1 + R V5 >35 mm; Cornell S V3 + R aVL >28 mm (♂)/>20 mm (♀); R aVL ≥11 mm.
• RVH: V1 tall R >7 mm or R/S ≥1; deep S in V6; V1–V2 strain.
• WPW: short PR <120 ms, wide QRS >120 ms, delta wave; Type A dominant R V1, Type B dominant S V1; pre-excited AF ~300 bpm.
• HCM ECG: LVH, ST/T changes, abnormal Q waves inferolateral leads.

Surgical / procedural indications

• AS → AVR: all symptomatic severe; asymptomatic if EF <50%, peak velocity >5.5 m/s, PA pressure >60 mmHg, velocity ↑ >0.3 m/s/yr, or exercise symptoms; bicuspid + ascending aorta >50 mm or expanding >5 mm/yr.
• AR → surgery: symptomatic severe; asymptomatic if EF ≤50%, end-diastolic >70 mm or end-systolic >50 mm.
• MR → surgery: symptomatic severe; asymptomatic if end-systolic >40 mm, EF <60%, or AF/pulmonary HTN (stricter than aortic — LV unloads into LA).
• MS → BMV: MVA ≤1.5 cm² + symptoms/PHTN + pliable valve; contraindicated if heavy calcification, more than mild MR, or LA thrombus (TOE mandatory pre-BMV).
• IE → V-HEART: Valve dysfunction→HF, Heart failure, Embolism (recurrent), Abscess (paravalvular), Resistant organism, large vegeTation >10 mm; post-stroke delay surgery 1 month.

ECG fundamentals (numbers worth having)

• Paper: small square 0.04 s (0.1 mV), big square 0.2 s; 25 mm/s; 10 mm = 1 mV.
• Leads → artery: II/III/aVF inferior (RCA); I/aVL high lateral + V5/V6 low lateral (LCx); V1/V2 septal + V3/V4 anterior (LAD).
• Rate: regular = 300 ÷ big squares (or 1500 ÷ small); irregular = QRS in 30 big squares × 10.
• Axis: normal −30 to +90 (I+, III+); LAD −30 to −90 (I+, III−); RAD +90 to +180 (I−, III+); extreme both negative.
• Normal values: PR 120–200 ms; QRS <110–120 ms; QTc prolonged >440 (♂)/>460 ms (♀), >500 = torsades risk.
• Acute ischaemia: new STE ≥1 mm (V2–V3: ≥2 mm ♂≥40, ≥2.5 ♂<40, ≥1.5 ♀) in 2 contiguous leads; STD ≥0.5 mm; ischaemic T inversion symmetrical.
• Pathological Q: >1 mm wide (>0.04 s) AND >2 mm deep, OR >25% of following R, in 2 contiguous leads.
• Atrial enlargement: RAE (P pulmonale) tall peaked P >2.5 mm in II; LAE (P mitrale) broad >3 mm/notched P.
• Low voltage: QRS <5 mm all limb and/or <10 mm all chest leads (sum I+II+III <15 mm); + electrical alternans → tamponade.
• STEMI evolution: hyperacute T (0–6 h) → ST elevation + Q begins 8–12 h → T inversion (24 h–3 wk) → ST normalises, Q persists; persistent ST elevation >3 wk = LV aneurysm.

Discriminators that decide questions

1. UA vs NSTEMI — identical clinically and on ECG (ST depression/T-changes); the troponin is the only feature — negative = UA, positive = NSTEMI.
2. Mobitz I (Wenckebach) vs Mobitz II — Mobitz I = progressive PR lengthening then dropped beat, block at AV node, benign (observe/atropine); Mobitz II = PR fixed with dropped beats + wide QRS, infranodal (His), unreliable escape → permanent pacemaker.
3. HCM vs AS — same angina + syncope + dyspnoea triad, but HCM murmur increases with Valsalva/standing (↓ afterload) while AS decreases; HCM murmur ↓ on squatting.
4. LBBB vs RBBB (what's masked) — LBBB masks MI, ischaemia, ventricular enlargement AND hemiblock; RBBB masks only ischaemia and enlargement — MI is still diagnosable in RBBB. New LBBB + chest pain = treat as STEMI.
5. RCM/amyloid vs constrictive pericarditis — both show Kussmaul's + raised JVP + right-HF picture; constrictive shows thickened/calcified pericardium (egg-shell) on CT/MRI + pericardial knock, and cardiac catheterisation distinguishes them.

Buzzword → answer (the vignette reflex)

• Curschmann spirals + Charcot-Leyden crystals (mucous plugs) → bronchial asthma
• Eggshell calcification of hilar lymph nodes → silicosis (pathognomonic)
• Ferruginous bodies (barbell golden-brown rods, Prussian blue +) → asbestos / asbestosis
• Comet tail sign (round opacity, irregular outline) → rounded atelectasis (asbestos)
• Signet ring sign (airway > artery) on HRCT → bronchiectasis
• Lupus pernio (facial lesion) → sarcoidosis (pathognomonic); non-caseating granuloma → sarcoidosis
• Caseating granuloma + Langhans giant cells + central caseous necrosis → TB tubercle
• Bulging fissure sign (RUL, DM/alcoholic) → Klebsiella / Friedlander's pneumonia
• Lady Windermere (RML + lingula nodular bronchiectasis, elderly woman) → NTM / MAC
• Fungus ball in a pre-existing (old TB) cavity → aspergilloma
• "Cannonball" nodules (multiple round nodules) → lung metastases
• Pleural rind encasing lung + Calretinin⁺ / TTF-1⁻ → malignant mesothelioma
• Hampton's hump (peripheral wedge infarct) / S1Q3T3 → pulmonary embolism
• Hyaline membranes (histological hallmark) → ARDS
• Crazy paving + milky BAL with foamy macrophages → PAP; headcheese sign → hypersensitivity pneumonitis
• Sail sign → LLL collapse; Luftsichel sign (air crescent) → LUL collapse
• Salt-and-pepper chromatin + nuclear molding → SCLC; keratin pearls + intercellular bridges → squamous cell carcinoma
• Pancoast (apical) tumour → Horner's syndrome
• "Angel wings" (massive upper-lobe PMF) → complicated coal worker's pneumoconiosis

Imaging / spirometry / histology → diagnosis

Criteria / staging / scores at a glance

• GINA 2025 asthma = chronic airway inflammation + variable symptoms + variable expiratory airflow limitation (asthma = variable, COPD = persistent).
• Asthma dx: pre-BD FEV1/FVC <80%, FEV1 <80% pred; reversibility ↑≥200 mL AND ≥12% post-salbutamol; PEF diurnal variability >10%; bronchial challenge fall in FEV1 ≥20%.
• Life-threatening asthma: confusion, hypotension, RR >30, SpO₂ <90%, silent chest.
• GINA discharge: SpO₂ >94% RA, PFT >60–80% predicted, step-up + review 1–2 wk.
• COPD (GOLD 2025) = post-BD FEV1/FVC <70%.
• GOLD severity (post-BD FEV1 %pred): 1 ≥80% · 2 50–<80% · 3 30–<50% · 4 <30% (FEV1 <50% = Roflumilast threshold).
• GOLD ABE: A = 0–1 exac (no hosp) + mMRC 0–1 or CAT <10 → single BD; B = 0–1 exac + mMRC ≥2 or CAT ≥10 → LABA+LAMA; E = ≥2 moderate exac or ≥1 hosp → LABA+LAMA (+ICS if eos ≥300).
• mMRC 0–4; ≥2 = highly symptomatic. CAT <10 = Group A, ≥10 = Group B.
• COPD exacerbation = worsening symptoms over <14 days, usually infection.
• IDSA/ATS severe pneumonia = 1 major (septic shock needing vasopressors / resp failure needing MV) OR 3 minor (RR ≥30, IV-fluid-corrected hypotension, hypothermia, confusion, leukopenia <4,000, thrombocytopenia <100,000, BUN ≥20, P:F ≤250, multilobar).
• CURB-65: Confusion (new) · Urea >7 mmol/L (20 mg/dL) · RR >30 · SBP <90 or DBP <60 · age >65. Score 0–1 home, 2 ward, 3–5 ICU.
• MAFIA PCC (anti-Pseudomonal): Meropenem, Aminoglycosides, Fluoroquinolones (NOT Moxifloxacin), Imipenem, Aztreonam, Piperacillin-tazobactam, Ceftazidime, Cefepime.
• Responsive pneumonia 72h (all 7): T ≤37.8°C, HR ≤100, RR ≤24, SBP ≥90, SpO₂ ≥90% RA, normal mental status, normal oral intake.
• CAP treatment duration: 3–4 d non-severe stable; ≥5 d severe/deteriorating; 7+ d Egypt.
• Corticosteroid in CAP: severe CAP + (septic shock OR P:F <300 OR rapid progression ≤3 d).
• Lobar pneumonia stages: congestion 1–2 d → red hepatization 3–4 d → grey hepatization 1 wk → resolution 1–2 wk.
• TST positivity (induration): ≥5 mm = HIV / recent contact / old TB on CXR / immunosuppressed; ≥10 mm = recent arrival <5 yr / IVDU / high-risk settings / DM, silicosis, CKD, steroids, malignancy; ≥15 mm = no risk factor.
• ADA cut-offs: CSF >8 U/L (TB meningitis) · ascitic >36 U/L · pleural >70 IU/L highly suggestive TB, <40 excludes, >40 + fluid/serum ratio ≥2 = TB effusion.
• QFT-G (IGRA) vs TST: IGRA = ESAT-6 + CFP-10, no BCG cross-react, higher specificity, 1 visit, 24 h (blood processed within 12 h); TST = PPD single, BCG false-positive, 2 visits, 48–72 h.
• TB regimen (new): 2 mo HRZE → 4 mo HR. Daily/daily optimal; intermittent 3×/wk only with DOT and NOT HIV.
• HRZES daily doses (mg/kg): H 5 (max 300) · R 10 (max 600) · Z 25 · E 15 · S 15. Streptomycin = only injectable first-line.
• TB monitoring: sputum at 2 mo + completion; LFTs (AST/ALT/bili/CBC) twice weekly first 2 wk then monthly.
• MDR-TB = resistance to both Isoniazid + Rifampicin.
• Light's criteria (exudate if any one): pleural/serum protein >0.5; pleural/serum LDH >0.6; pleural LDH >2/3 ULN serum.
• Scadding CXR staging (NOT progressive): I bilateral hilar adenopathy · II hilar + infiltrates · III infiltrates only · IV fibrosis/honeycombing.
• BAL CD4/CD8: sarcoidosis ≥2.5 · hypersensitivity pneumonitis <1 (neutrophilia → worse prognosis).
• Reid classification (mildest → severest): cylindrical → varicose → cystic (saccular).
• Runyon (NTM): 1 slow photochromogen (kansasii, marinum) · 2 slow scotochromogen (scrofulaceum) · 3 slow non-photochromogen (avium/MAC) · 4 fast growers <7 d (fortuitum, chelonae, abscessus).
• NTM pulmonary dx = ALL radiological (symptoms + cavitary/nodular lesion + exclude other) + ONE microbiological (2 positive sputum cultures OR 1 bronchial wash OR biopsy + histology).
• Lung cancer %: 95% of lung tumours are primary; NSCLC 85% (squamous 30%, non-squamous 70% → adeno 90% / large-cell 10%); SCLC 15%. Smoking = 80% of cases, 60× in heavy smokers.
• NSCLC TNM: T1–T4 (size + local invasion), N0–N3, M0/M1. Mets: liver, brain, bone, adrenal.
• SCLC: limited (one hemithorax, single radiation port) vs extensive.
• Berlin ARDS: acute ≤1 wk, bilateral opacities, not cardiac, P:F with PEEP ≥5. Severity by P:F — mild >200, moderate 100–200, severe ≤100.
• Revised Geneva (PE): clinical probability → PE-unlikely = D-dimer, PE-likely = CTPA.
• Simplified PESI (each 1 pt): age >80, chronic cardiopulmonary disease, cancer, HR ≥110, SBP <100, SaO₂ <90%. sPESI ≥1 = higher 30-day mortality risk.
• PE risk strat: low = sPESI 0 + no RV strain · intermediate = sPESI ≥1 or RV strain · high = haemodynamic instability → systemic thrombolysis.
• Pneumoconiosis latency: asbestosis 20–30 yr (<10 yr if very heavy) · mesothelioma up to 40 yr · chronic silicosis >15 yr · acute silicosis within months.

Discriminators that decide questions

1. Obstructive vs restrictive (spirometry step 1 = FEV1/FVC): obstructive = FEV1/FVC <0.7 (or <LLN), ↓FEV1, ↓FEF25–75, FVC normal/↓, TLC normal/↑; restrictive = normal/↑ FEV1/FVC, ↓FVC, ↓TLC.
2. Asthma vs COPD: asthma = variable + reversible (FEV1 ↑ ≥200 mL AND ≥12%), DLCO normal/high; COPD = persistent, post-BD FEV1/FVC <70%, low DLCO if emphysema.
3. Transudate vs exudate: exudate if any Light's criterion met (protein ratio >0.5 / LDH ratio >0.6 / LDH >2/3 ULN); transudate = heart failure, cirrhosis, hypoalbuminaemia, nephrotic; exudate = infection, malignancy, TB, PE, autoimmune.
4. Mediastinal shift AWAY vs TOWARD: away = tension pneumothorax / massive effusion (fluid/air pushes); toward = atelectasis / lobar collapse / fibrosis / lobectomy (volume loss pulls).
5. Mesothelioma vs adenocarcinoma (IHC): Calretinin⁺ / TTF-1⁻ = mesothelioma; TTF-1⁺ / Napsin-A⁺ = primary lung adenocarcinoma. (BAL CD4/CD8 ≥2.5 sarcoid vs <1 HP is the parallel ILD discriminator.)

Buzzword → answer (the vignette reflex)

• Acetone (fruity) breath + Kussmaul respiration → DKA (mostly T1DM)
• Explosive onset in a young lean patient with ketoacidosis → T1DM (diagnostic)
• Bronze hyperpigmentation + hyponatraemia + hyperkalaemia + hypoglycaemia → Addison's (primary adrenal insufficiency)
• "Spells"/paroxysms — headache, perspiration, palpitations, pallor → Phaeochromocytoma (5 Ps)
• Purple striae + moon face + buffalo hump + thin arms & legs → Cushing's syndrome
• Chvostek + Trousseau signs → Hypocalcaemia (pathognomonic of neuromuscular excitability)
• "Stones, bones, groans, moans" → Hypercalcaemia
• Non-pitting myxedema + loss of outer ⅓ eyebrows (Queen Anne's sign) + slow-relaxing reflexes → Hypothyroidism
• Pretibial myxedema + diffuse goitre + bruit + exophthalmos → Graves' disease (pretibial myxedema pathognomonic)
• Exquisitely tender thyroid + ESR up to 100 + low RAI uptake → Subacute (de Quervain's) thyroiditis
• Orphan Annie-eyed nuclei on FNA → Papillary thyroid carcinoma
• Amyloid stroma + high calcitonin → Medullary thyroid carcinoma (parafollicular C-cell)
• Hürthle cells + lymphocytic infiltration on FNA → Hashimoto's thyroiditis
• Rib notching + "three sign" on CXR + arm–leg BP discrepancy → Coarctation of the aorta
• Mucosal neuromas (lips/tongue) + marfanoid habitus → MEN 2B
• Craving cold liquids + polyuria (>3 L/day) → Diabetes insipidus
• Pemberton's sign (arms overhead → facial plethora + JVD) → Retrosternal goitre
• Whipple's triad (symptoms + low glucose + relief on raising glucose) → Hypoglycaemia
• Elderly obese woman in winter, hypothermia, hoarse voice, coma → Myxedema coma (sepsis = #1 precipitant)

Dynamic test / hormone pattern → diagnosis

Criteria / staging / scores at a glance

• Diabetes dx — FPG ≥7.0 mmol/L (126) · A1C ≥6.5% (not valid in suspected T1DM) · 2h-OGTT ≥11.1 (200) · random ≥11.1 + symptoms. Asymptomatic → repeat on another day.
• Prediabetes — IFG FPG 6.1–6.9 · IGT 2h-PG 7.8–11.0 · A1C 6.0–6.4%.
• GDM screening (24–28 wks) — one-step 75g (fasting ≥92 / 1h ≥180 / 2h ≥153 mg/dL, any one) OR two-step 50g GLT → if 1h ≥130–140 → 100g OGTT (≥2 values).
• DKA — glucose >250 mg/dL · bicarbonate <15 mEq/L · pH <7.3 · ketonaemia + ketonuria (triad: hyperglycaemia + ketosis + metabolic acidosis).
• HHS — glucose >600 mg/dL · osmolarity >310 mOsm/L · dehydration + depressed sensorium · NO ketoacidosis.
• DM targets — A1C <7.0% · preprandial 90–130 · postprandial <180 mg/dL · BP <130/80 · LDL <100 / TG <150 / HDL >40 mg/dL.
• Acromegaly OGTT — GH >10 ng/mL after oral glucose = diagnostic; normal glucose suppresses GH; IGF-1 elevated.
• Cushing's screening — overnight 1 mg DST, <1.8 mcg/dL (50 nmol/L) excludes; 24h urinary free cortisol elevated; loss of cortisol circadian rhythm.
• DST variants — overnight low-dose 1–2 mg (screen) · 48h low-dose 0.5 mg q6h (confirm) · 48h high-dose 2 mg q6h (localise); failure to suppress = cortisol >50 nmol/L.
• Synacthen — short 250 µg IV, peak >550 nmol/L (>18 mcg/dL) excludes primary; long depot ×3 days differentiates primary vs secondary.
• Water deprivation — DI confirmed if plasma osmo >300 with urine osmo <600 (stop if weight ↓3%).
• ITT — gold standard GH/cortisol reserve; valid only if glucose <2.5 mmol/L; contraindicated in epilepsy / IHD.
• GH deficiency cutoffs — adult deficient <2.7 (not deficient >6) µg/L · child deficient <4.5 (not deficient >7.5) µg/L.
• Diabetes classification (ADA) — 4 classes: Type 1 · Type 2 · Gestational · Specific types (monogenic, exocrine pancreas, drug/chemical).
• CAH enzymes — 21-OH (90%): ↓mineralocorticoid, ↑androgens, marker 17-OH-progesterone, low BP (salt-wasting) · 11β-OH: ↑DOC, ↑androgens, marker 11-deoxycortisol, high BP · 17α-OH: ↑mineralocorticoid, ↓androgens, high BP, undervirilised ♂. Autosomal recessive.
• Hyperaldosteronism — Primary (Conn's): low renin/high aldo · Secondary: high renin/high aldo · Pseudo: low renin/low aldo (Cushing's, liquorice, SAME, Liddle's). All → HTN.
• MEN — MEN 1 (3 Ps: Pituitary+Parathyroid+Pancreatic, Menin gene) · MEN 2A (MTC+Phaeo+HyperPTH, RET) · MEN 2B (MTC+Phaeo+mucosal neuromas+marfanoid, no PHPT, RET) · FMTC (MTC only, RET). MEN 2 = AD, ~100% penetrance.
• Polyglandular autoimmune — Schmidt (Addison + Hashimoto) · PAS-1 (APECED, AIRE gene, AR: Addison + hypoPTH + mucocutaneous candidiasis) · PAS-2 (Addison + T1DM + Hashimoto's/Graves').
• Rule of 10s (phaeo) — 10% extra-adrenal / bilateral / malignant / familial / normotensive.
• TFT patterns — TSH normal range 0.5–5 µU/ml; assess with free hormone.
• ACR TI-RADS scoring — taller-than-wide = 3 pts · punctate echogenic foci = 3 · very hypoechoic = 3 · extra-thyroidal extension = 3.
• TI-RADS categories & FNA — TR1 0.3% (no FNA) · TR2 1.5% (no) · TR3 4.8% (FNA ≥2.5 cm) · TR4 9.1% (≥1.5 cm) · TR5 35% (≥1.0 cm). Follow-up: TR3 ≥1.5 · TR4 ≥1.0 · TR5 ≥0.5 cm.
• Bethesda FNA — I non-diagnostic 5–10% · II benign 0–3% · III AUS/FLUS 6–18% · IV follicular neoplasm 10–40% · V suspicious 45–60% · VI malignant 94–96%. Molecular testing (ThyroSeq) avoids surgery in ~60% of III/IV.
• NO SPECS (Graves' eye) — 0 none · 1 signs only (lid retraction/lag) · 2 soft tissue · 3 proptosis · 4 extraocular muscle · 5 corneal · 6 sight loss.
• Thyroid cancer prognosis — Papillary (5% 10-yr mortality, 96% 5-yr survival) > Follicular (10%, 91%) > Hürthle (15%) > Medullary (20%, 85%) > Anaplastic (7% 5-yr survival).
• ATA post-op risk (WDTC) — Low: no RAI, TSH 0.5–2.0 · Intermediate: 30 mCi, TSH 0.1–0.5 · High: 100–150 mCi, TSH <0.1 mU/L.
• Hyperparathyroidism — Primary: ↑Ca ↓PO4 ↑PTH (adenoma) · Secondary: ↓/normal Ca ↑PO4 ↑PTH (CKD) · Tertiary: ↑Ca ↑PO4 very-↑PTH (post-transplant, autonomous).
• DEXA / FRAX — T-score <−2.5 = osteoporosis (osteopenia −1 to −2.5); Z-score flags secondary osteoporosis; FRAX = 10-yr fracture probability (Red = treat / Orange = measure BMD / Green = reassure).
• Parathyroidectomy (asymptomatic PHPT), any one — age <50 · Ca >1 mg/dL over ULN · CrCl <60 · T-score <−2.5 · 24h urine Ca >400 mg · vertebral fracture/nephrolithiasis/nephrocalcinosis · unable/unwilling for surveillance.
• Hypercalcaemic crisis — corrected Ca >3.5 mmol/L; normal saline up to 200 mL/h; avoid diuretics; pamidronic acid 60–90 mg IV; delay surgery until Ca <3 mmol/L.
• T2DM step-up — monotherapy (metformin) → dual (+1 agent if A1C not met after ~3 mo or ≥9%) → triple (+2 agents) → insulin if A1C <7% not reached on max orals.

Discriminators that decide questions

1. T1DM vs T2DM — T1: islet autoantibodies usually present, C-peptide undetectable/low, first-line insulin, DKA common; T2: antibodies absent, C-peptide normal/high, non-insulin agents, DKA rare.
2. DKA vs HHS — DKA: glucose >250, bicarb <15, pH <7.3, ketones present (mostly T1DM); HHS: glucose >600, osmolarity >310, NO significant ketoacidosis (mostly T2DM, enough insulin to suppress ketogenesis but not hyperglycaemia).
3. Primary vs secondary hyperaldosteronism — Primary (Conn's): low renin / high aldosterone (inverse); Secondary: high renin + high aldosterone (direct, e.g. renal artery stenosis; normotensive causes = Gitelman's/Bartter's).
4. Primary vs secondary adrenal insufficiency — Primary (Addison's): pigmented + salt-wasting, high ACTH, aldosterone low/renin high, needs fludrocortisone; Secondary: not pigmented, no salt-wasting, low/inappropriately-normal ACTH, aldosterone preserved, NO fludrocortisone.
5. Central vs nephrogenic DI — Central: desmopressin makes urine concentrate (ADH secretion deficit); Nephrogenic: desmopressin → no change (end-organ ADH unresponsiveness — lithium, hypercalcaemia, hypokalaemia).
6. Papillary vs follicular carcinoma — Papillary: lymphatic spread, multifocal, Orphan Annie nuclei, good prognosis; Follicular: bloodstream (haematogenous) spread, unifocal, capsular/vascular invasion diagnostic, worse prognosis.

Buzzword → answer (the vignette reflex)

• Sub-epithelial "humps" on EM → Post-streptococcal GN (PIGN) (granular IgG/IgM/C3 in BM zone)
• Linear IgG deposits along the GBM (IF) → Goodpasture's / anti-GBM (targets α3 chain of type IV collagen)
• Mesangial IgA + C3 on IF → IgA nephropathy (Berger's)
• Anti-PLA2R antibodies → primary Membranous Nephropathy (podocyte antigen)
• LM normal, IF no deposits, EM diffuse podocyte foot-process effacement → Minimal Change Disease
• Wavy / basketweave split GBM on EM → Alport syndrome (type IV collagen mutation)
• Muddy brown granular casts → Acute Tubular Necrosis
• Flea-bitten kidney; fibrinoid necrosis + onion-skin arteriosclerosis → Malignant hypertension (BP >200/120)
• Tubular "thyroidisation" (dilated tubules, colloid casts) → Chronic pyelonephritis
• Dipstick +ve for blood but NO RBCs on microscopy → Rhabdomyolysis (myoglobin) / haemoglobinuria
• Eosinophiluria + interstitial eosinophil infiltrate sparing glomeruli → Drug-induced AIN
• "Beaded" appearance on angiography (mid-to-distal artery) → Fibromuscular dysplasia (typical age 35, female)
• Ring sign + clubbed calyces on IVP; bilateral, no cortical loss → Papillary necrosis (analgesic nephropathy)
• Saturnine gout + disproportionate hyperuricaemia → Lead nephropathy (welders, battery workers)

Urinary / biopsy finding → diagnosis

Criteria / staging / scores at a glance

• KDIGO CKD diagnosis — GFR <60 mL/min/1.73 m² OR ≥1 marker of kidney damage (albuminuria ACR >30 mg/g or >3 mg/mmol; sediment / tubular / histological / structural abnormality; transplant Hx), present >3 months.
• ADPKD US criteria (positive FHx) — <30 y: 2 cysts (uni/bilateral); 30–59 y: 2 cysts in each kidney; ≥60 y: 4 cysts in each kidney (stricter with age).
• RIFLE — Risk (sCr ×1.5 or ≥0.3 mg/dL; UO <0.5 mL/kg/h ×6 h) · Injury (sCr ×2; UO <0.5 ×12 h) · Failure (sCr ×3, or ≥0.5 mg/dL if baseline >4.0; UO <0.3 ×24 h or anuria ×12 h) · Loss (complete loss >4 wk) · ESRD.
• AKIN — Stages 1–3 = first 3 RIFLE grades (drops Loss/ESRD); any patient on RRT = automatically Stage 3.
• KDIGO AKI — St1: sCr 1.5–1.9× baseline OR ≥26.5 µmol/L (0.3 mg/dL) rise, UO <0.5 mL/kg/h for 6–12 h · St2: sCr 2–2.9× · St3: sCr 3× OR start RRT, anuria ≥12 h. <18 y: eGFR <35.
• KDIGO GFR categories — G1 ≥90 · G2 60–89 · G3a 45–59 · G3b 30–44 · G4 15–29 · G5 <15 (ESRD → dialysis). ACR (mg/mmol) A1 <3 · A2 3–30 · A3 >30.
• eGFR equations — CKD-EPI (most used, more accurate at high GFR) vs MDRD (older, less accurate at high GFR); markers = serum creatinine + cystatin C. Measured-GFR gold standard = inulin clearance.
• Lupus nephritis Classes I–VI — I minimal mesangial · II mesangial proliferative · III focal (<50% glomeruli) · IV diffuse (≥50%) + crescents (most severe) · V membranous (sub-epithelial, thickened GBM on silver stain) · VI advanced sclerosis. Deposits: III+IV sub-endothelial, I–V mesangial, V sub-epithelial.
• RPGN types by IF — I linear (anti-GBM / Goodpasture's) · II granular immune-complex (SLE, post-infective) · III pauci-immune (Wegener's granulomatosis, PAN).
• VUR grades 1–5 — 1 ureter only · 2 up to renal pelvis, no dilatation · 3 mild dilatation of ureter + PCS · 4 moderate dilatation, blunted fornices, preserved papillary impressions · 5 severe dilatation, loss of fornices + papillary impressions (Grades 4+5 → surgery).
• Pre-renal vs intrinsic AKI (urine chemistry) — SG >1.020 vs <1.010 · U osm >500 vs <350 · U Na <10 vs >20 · FENa <1% vs >1% · BUN:Cr >20:1 vs <20:1 · Urea:Cr >40:1 vs <40:1. FENa = [(U Na × serum Cr) / (U Cr × serum Na)] × 100.
• Urinary casts (7 types) — fatty = nephrotic · granular = nonspecific, esp. ATN · hyaline = dehydration/exercise/diuretics · RBC = glomerular bleeding · renal tubular epithelial cell = tubular necrosis/transplant rejection · WBC = pyelonephritis/interstitial · waxy = advanced/chronic renal failure.

Discriminators that decide questions

1. Nephritic vs nephrotic — Nephritic: oliguria, haematuria, hypertension, mild proteinuria (<3 g/day), mild oedema, RBC casts. Nephrotic: proteinuria >3.5 g/day + serum albumin <3.5 g/dL + generalised oedema (± hyperlipidaemia, lipiduria, oval fat bodies). MPGN = mixed nephrotic + nephritic.
2. Complement pattern — ↓ C3, normal C4 = alternative pathway (PIGN, MPGN type 2) · normal C3 + normal C4 (IgA nephropathy) · ↓ C3, ↓ C4 = classical pathway (lupus nephritis; MPGN types 1 & 3).
3. PIGN vs IgA nephropathy — PIGN: haematuria 1–4 weeks after Group A strep, ↓ C3, sub-epithelial humps, only 1–2% → CKD. IgA: synpharyngitic haematuria 1–2 days after URTI, normal complement, mesangial IgA + C3, 50% → CKD.
4. Pre-renal vs established ATN — Pre-renal: FENa <1%, U Na <10, U osm >500, BUN:Cr >20:1 → give fluid challenge (250 mL crystalloid). Established ATN: FENa >1%, U Na >20, U osm <350, muddy brown casts → DO NOT give fluid, supportive only.
5. MCD vs FSGS — MCD: steroid-responsive, LM normal, commonest nephrotic in children. FSGS: often steroid-resistant, segmental sclerosis from juxtamedullary zone (deep biopsy needed), almost all → CKD.

Buzzword → answer (the vignette reflex)

• Kayser-Fleischer rings (slit lamp) + low ceruloplasmin → Wilson's disease (ATP7B, autosomal recessive)
• Caudate atrophy on MRI + chorea + CAG >40 repeats → Huntington's (autosomal dominant, anticipation)
• Albuminocytologic dissociation (CSF) → Guillain-Barré (steroids DO NOT help — vs CIDP)
• Thunderclap "worst of my life", occipital + xanthochromia on LP → subarachnoid haemorrhage (aneurysm 70%)
• Lucid interval + biconvex/lens-shaped CT, doesn't cross sutures → epidural haematoma (middle meningeal artery at pterion)
• Crescent-shaped CT, crosses suture lines, bridging veins, elderly + atrophy → subdural haematoma
• Hyperdense MCA sign → early ischaemic stroke thrombosis
• Oligoclonal bands (IgG CSF > serum) + Lhermitte's / Uhthoff's / INO → multiple sclerosis
• RAPD + red desaturation + pain on eye movement → optic neuritis (often first MS presentation)
• AQP4-IgG + longitudinally extensive myelitis (>3 vertebral segments) → NMO (Devic's)
• Heliotrope rash + Gottron's papules + proximal weakness → dermatomyositis (adults → screen malignancy)
• Jaw claudication + scalp tenderness + ESR >50 mm/h, >50 y → giant cell arteritis (ophthalmic emergency)
• Young woman, high BMI + papilloedema + pulsatile tinnitus → idiopathic intracranial hypertension
• Restlessness/agitation + unilateral autonomic (lacrimation, ptosis, miosis) → cluster headache (TAC)
• Gowers sign + calf hypertrophy + CK up to 10,000 → Duchenne (X-linked, absent dystrophin)
• Fatigable weakness + ptosis/diplopia, sensory + reflexes normal → myasthenia gravis (ACh-R Ab, thymoma)

Lesion site / sign → deficit or diagnosis

Criteria / staging / scores at a glance

• McDonald (MS): DIS + DIT + no better explanation. 2010 DIS = 4 regions (periventricular, juxtacortical, infratentorial, spinal cord); 2017 = OCBs can substitute for DIT in CIS; 2024 = optic nerve as 5th DIS site + kFLC + CVS + PRL.
• Migraine (IHS): 4–72 h; ≥2 of 4 (unilateral, throbbing, mod/severe, aggravated by movement); ≥1 of 2 (N/V or photo+phonophobia); chronic if ≥15 days/month.
• TTH (IHS): 30 min–7 days; ≥2 of 4 (bilateral, non-throbbing, mild/mod, not aggravated); no N/V; one or neither photo/phonophobia.
• MOH: headache ≥15 days/month; triptans/opioids/combos ≥10 days/month OR simple analgesics ≥15 days/month; ≥3 months overuse; resolves within 2 months.
• Tourette: ≥2 motor tics + ≥1 vocal tic; duration >1 y; onset <18 y (typical 5–10 y).
• Huntington's genetics: AD; HTT gene, CAG repeat expansion; normal 9–36; disease threshold >40; anticipation.
• GBS (functional): AIDP; symmetric ascending weakness + areflexia; CSF albuminocytologic dissociation; nadir by 4 weeks in 90%.
• NIHSS: 0 no stroke · 1–4 minor · 5–15 moderate · 16–20 mod-severe · 21–42 severe (max 42).
• ABCD2 (TIA): Age >60 (1), BP ≥140/90 (1), unilateral weakness (2), speech w/o weakness (1), duration 10–59 min (1) / ≥60 min (2), DM (1). Score 0–3 low (1.0%), 4–5 mod (4.1%), 6–7 high (8.1%) 2-day stroke risk.
• MS disease courses: RIS, CIS, RRMS, SPMS, PPMS; modifiers RAW (relapse-associated worsening) vs PIRA (progression independent of relapse activity).
• Intracranial haemorrhage classification: extradural (skull–dura), subdural (dura–arachnoid), subarachnoid (arachnoid–pia), intracerebral (parenchyma).
• DAI grades: I widespread corpus callosum/WM/brainstem; II + focal haemorrhage in corpus callosum; III + rostral brainstem. Histology = axonal spheroids ("retraction balls").
• Cerebral oedema: vasogenic (BBB breakdown; tumour/abscess/contusion; dexamethasone) vs cytotoxic (Na/K pump failure; ischaemia/hypoxia; mannitol).
• SOL herniation grades: I <2 cm from lesion; II >2 cm, <½ hemisphere; III >2 cm, >½, no midline shift; IV >2 cm, >½, with midline shift (subfalcine).
• Hyperkinetic movement disorders: chorea, dystonia, myoclonus, tremor, tic (less common: ballism, athetosis, stereotypy).
• Dystonia distribution: focal, segmental (≥2 contiguous), hemidystonia, multifocal (≥2 non-contiguous), generalised (trunk + ≥2 parts).
• Dystonia aetiology: primary (isolated), dystonia-plus (+parkinsonism/myoclonus), secondary (lesion/drug/tardive).
• CMT (HMSN) classification: groups HMSN/HMN/HSN-HSAN; onset early-infantile <2 y, childhood 2–10, juvenile 10–20, adult 20–50, late adult >50; demyelinating vs axonal; PMP22 CNV most common.
• Muscular dystrophies: congenital, Duchenne, Becker, limb girdle, myotonic, FSHD, Emery-Dreifuss, occulopharyngeal, distal.
• Myopathy umbrella: hereditary (congenital, dystrophy, distal) vs idiopathic/acquired (inflammatory, immune, infection/HIV, endocrine-metabolic, drugs/toxins, malignancy).
• Aphasia: Broca = expressive; Wernicke = receptive.
• Dysarthria: cerebellar, bulbar (LMN flaccid), pseudobulbar (UMN spastic), extrapyramidal.
• Watershed areas: ACA-MCA = high parasagittal cortex; MCA-PCA = posterior parietal/occipital; setting = prolonged hypotension.
• ICP thresholds: normal 7–15 mmHg; borderline 20–25; raised >25; IIH LP opening pressure >25 cm H₂O; CPP target >70 mmHg.
• Cushing triad: ↑BP + bradycardia + irregular respiration (± pupil dilation) = late sign of impending herniation.
• Rule of 4 (brainstem): 4 midline structures (motor pathway, medial lemniscus, MLF, motor nucleus) + 4 lateral "S"; 4 midline CNs = III, IV, VI, XII; 4 lateral CNs = V, VII, IX, XI.
• UMN vs LMN: tone spastic vs flaccid; reflexes brisk/clonus vs absent; plantar upgoing vs downgoing; fasciculations absent vs present; atrophy late vs early/marked.
• VITAMIN CD: Vascular, Infection/Inflammatory, Traumatic, Autoimmune, Metabolic, Idiopathic/Iatrogenic, Neoplastic, Congenital, Degenerative/Drug.
• CSF meningitis: bacterial = ↑↑ opening pressure, neutrophils, ↓ glucose, ↑↑ protein · viral = normal/mild ↑, lymphocytes, normal glucose, ↑ protein · fungal = ↑, lymphocytes, ↓ glucose, ↑ protein.
• SNOOP red flags: Systemic, Neurologic, Onset (thunderclap <1 min), Onset age (<5 or >65 y), Pattern change, Precipitated by Valsalva, Postural, Papilledema, Pregnancy, Phenotype of rare headache.
• Syncope DDx: structural (aortic stenosis, cardiomyopathy, RV dysplasia), arrhythmia (VT, Brugada, long QT, AV block), reflex (vasovagal, carotid), situational (cough, micturition), postural (orthostatic/POTS), OSA.
• rt-PA windows: NINDS 1996 = 3 h; ECASS 3 (2008) = 4.5 h. Dose 0.9 mg/kg (max 90), 10% bolus then rest over 1 h; door-to-needle ≤60 min.
• Mechanical thrombectomy: up to 6 h (extended windows possible); targets Carotid, M1/M2, A1/A2.
• IIH ladder: weight loss (first-line) → acetazolamide/topiramate/furosemide → repeated LP (15–25 mL/session) → CSF shunt if vision threatened.
• Meningitis empiric: IV cefotaxime/ceftriaxone 2 g qds; add IV ampicillin 2 g qds if >55 y (Listeria); dexamethasone 10 mg qds ×4 d; prophylaxis single-dose ciprofloxacin OR rifampicin 600 mg bd ×2 d.
• GCA treatment: long-term oral steroids 1 mg/kg; monitor ESR.
• TBI initial management: 12 steps (GCS → wound exam → elevate head → ABC → repeat GCS → neuro exam → anticonvulsants → osmotic diuretics if ↓GCS → C-spine imaging → CT brain → polytrauma survey → labs).
• Brainstem death: flat EEG + loss of corneal reflex; if not dead → craniectomy.
• Duroplasty grafts: autograft (fascia lata), xenograft (bovine pericardium), allograft (artificial).
• Post-stroke complications to prevent: painful shoulders, pressure sores, contractures, incontinence, malnutrition, aspiration pneumonia.
• Rehab DON'Ts: don't pull hemiparetic arm, don't squeeze fingers, don't leave in one position, don't catheterise if possible.
• Brain plasticity: dendritic growth + axonal arborisation post-stroke; rehab starts day 1 via MDT; "never too late".

Discriminators that decide questions

1. UMN vs LMN: UMN = ↑tone (spastic), brisk reflexes/clonus, upgoing plantar (Babinski), no fasciculations, late/disuse atrophy. LMN = ↓tone (flaccid), absent reflexes, downgoing plantar, fasciculations present, early/marked atrophy.
2. EDH vs SDH: EDH = biconvex/lens-shaped, does NOT cross sutures, arterial (middle meningeal at pterion), classic lucid interval. SDH = crescent-shaped, crosses suture lines, venous (bridging veins), elderly + dementia + atrophy; chronic SDH mimics stroke.
3. GBS vs CIDP: GBS = nadir <4 weeks, cranial/respiratory involvement, steroids DO NOT help. CIDP = slowly progressive >8 weeks, spares cranial/respiratory muscles, steroids DO work.
4. Migraine vs TTH: migraine = featureful (unilateral, throbbing, N/V, photo+phonophobia, aggravated by movement). TTH = featureless (bilateral, non-throbbing, no N/V, one or neither photo/phonophobia).
5. Syncope vs GTCS: duration <30 s vs 1–2 min; jerks multifocal/non-rhythmic vs rhythmic; tongue bite tip vs lateral; post-ictal <30 s vs 2–30 min; pale vs cyanosed. (Jerks during syncope do NOT make it a seizure.)

Buzzword → answer (the vignette reflex)

• Gottron's papules / heliotrope (purplish) eyelid rash → Dermatomyositis (Gottron's pathognomonic for DM; PM has NO rash)
• Keratoderma blenorrhagica → Reactive arthritis (pathognomonic)
• 1st MTP "podagra" → Gout (50–70% of first attacks)
• Needle-shaped, strongly negatively birefringent crystals (yellow ∥ to axis) → Gout (MSU)
• Rhomboid, weakly positively birefringent crystals (blue ∥ to axis) → Pseudogout (CPPD)
• Chondrocalcinosis (linear cartilage calcification) → CPPD (most common cause)
• Watermelon stomach / GAVE → limited SSc (CREST)
• Pencil-in-cup deformity on X-ray → Psoriatic arthritis
• Bamboo spine / dagger sign / Romanus shiny-corner → Ankylosing spondylitis
• Halo sign on temporal-artery ultrasound → Giant cell arteritis
• Positive pathergy test → Behçet's (also: aortic aneurysm on imaging = Behçet's or Takayasu)
• Jaccoud's arthropathy (reducible, non-erosive, correctable) → SLE
• Erysipelas-like lesion (lower leg) + recurrent polyserositis → FMF
• Asthma + eosinophilia → EGPA (Churg–Strauss); ENT + lung + kidney + cANCA → GPA (Wegener's)

Antibody → disease

Criteria / scores at a glance

• ACR 1987 RA (4/7): morning stiffness ≥1 hr, ≥3 joints swollen, hand-joint swelling, symmetric swelling, hand-X-ray erosions/decalcification, rheumatoid nodules, abnormal RF (asterisked 4 must be present ≥6 weeks).
• ACR/EULAR 2010 RA: 4 scored domains — joint involvement, serology, acute-phase reactants, symptom duration; entry = ≥1 joint with unexplained synovitis.
• ACR SLE: 4 of 11.
• Bohan & Peter PM/DM (5 pillars): proximal weakness + ↑ enzymes (CK/AST/ALT/LDH/aldolase) + abnormal EMG + muscle biopsy + rash (DM-specific).
• Inflammatory back pain (4/5, back pain >3 months): onset <40 yr, insidious, improves with exercise, no improvement with rest, night pain.
• GPA/Wegener's triad: ENT + lung + kidney (cANCA anti-PR3 >95%).
• EGPA/Churg–Strauss (Lanham 1984): asthma + eosinophilia + systemic vasculitis (>2 extrapulmonary organs) (pANCA anti-MPO).
• Reiter's triad: arthritis + urethritis + conjunctivitis.
• HSP tetrad: palpable purpura + GIT + arthritis/arthralgia + renal (biopsy = perivascular IgA).
• Behçet: recurrent oral ulcers (mandatory) + 2 of {genital ulcers, eye, skin, pathergy}.
• Scleroderma renal crisis: new-onset BP >150/85 + eGFR fall ≥30% + ↑ creatinine + MAHA + hypertensive retinopathy + proteinuria/haematuria + oliguria/anuria + flash pulmonary oedema (biopsy = thrombotic microangiopathy).
• ACR 1990 PAN: ≥3/10 criteria for classification.
• ACR 2020 Gout: initiate ULT during flare (conditional, with NSAID/colchicine/steroid cover); continue ULT indefinitely.
• FMF: clinical diagnosis — MEFV supports but cannot exclude.
• Modified Schober's (AS): 15 → <20 cm = limited lumbar flexion.
• Chest expansion (AS): normal 3–15 cm. SIJ stress: FABER (Flexion, Abduction, External Rotation). Cervical: occiput-to-wall / tragus-to-wall.
• Glucocorticoid dose (prednisone-equiv/day): Low ≤7.5 · Medium >7.5–≤30 · High >30–≤100 · Very high >100 · Pulse ≥250 ×1 day / few days.
• CRPS stages: 1 Acute 1–3 mo (warm/red, oedema) · 2 Dystrophic 3–6 mo (cold/cyanotic, osteoporosis) · 3 Atrophic late (contractures, waxy trophic skin).
• Sensitivity vs specificity: high Sn → neg rules OUT (screening); high Sp → pos rules IN (confirmation).
• WHO/ISN lupus nephritis: 1 normal LM · 2 mesangial · 3 focal proliferative · 4 diffuse proliferative · 5 membranous · 6 interstitial/tubular.
• Sacroiliitis X-ray grade (0–IV): 0 normal · I suspicious/hazy · II erosions + sclerosis, joint space preserved · III narrowing + partial ankylosis · IV bilateral ankylosis (fusion).
• Five PsA patterns: DIP 55–70% · asymmetric oligo (<5 joints) 30–50% · symmetric poly (RA-like) 15–70% · spondylitic 5–33% · arthritis mutilans 3–5%.
• RA joint distribution: MCP/PIP/MTP 90% · knees/wrists/ankles 80% · hip/elbow 50% · cervical spine 40% · TMJ/AC 30% · cricoarytenoid 10%.
• Vasculitis by vessel size: Large = GCA, Takayasu · Medium = PAN, Kawasaki · Small/medium (ANCA) = GPA, EGPA, MPA · Small = HSP, essential mixed cryoglobulinaemia · Variable = Behçet's.
• Joint-count / timing: mono 1 · oligo 2–4 · poly ≥5; acute <14 days · subacute 2–6 wk · chronic >6 wk.
• 4 A's of AS (extra-articular): Anterior uveitis (40%), Aortic valve/root (AR), Apical fibrosis, Amyloidosis.
• CREST: Calcinosis · Raynaud's · Oesophageal dysfunction · Sclerodactyly · Telangiectasia.
• Five ocular of RA: keratoconjunctivitis sicca, episcleritis, scleritis, scleromalacia, scleromalacia perforans (corneal melt = most severe).
• ANA pattern → association (next test): Homogeneous → SLE/MCTD (dsDNA) · Speckled → SLE/MCTD/Sjögren's (ENA) · Nucleolar → SLE/scleroderma (Scl-70) · Centromere → limited scleroderma/CREST · Cytoplasmic → myositis (Jo-1).
• ESR/CRP: both high (rise together) = active inflammation (RA/vasculitis/infection) or drug reaction; ESR high + CRP normal = SLE, Sjögren's (polyclonal IgG), cancer.
• CAN'T LEAP (under-excretion gout drugs): Cyclosporin, Alcohol, Nicotinic acid, Thiazides, Lasix, Ethambutol, Aspirin (low-dose), Pyrazinamide.
• Hyperuricaemia: serum urate >6.8 mg/dl (>360 µmol/l).
• Imaging cutoffs: OA = Kellgren–Lawrence 0–4; atlantodental interval (ADI) normal ≤3 mm adults / ≤5 mm children.

Discriminators that decide questions

1. Gout vs Pseudogout — Gout: MSU, needle, strongly negatively birefringent, yellow ∥ axis; X-ray = punched-out erosions with OVERHANGING edges + preserved joint space. Pseudogout: CPPD, rhomboid, weakly positively birefringent, blue ∥ axis; X-ray = chondrocalcinosis. (No crystal-dissolving therapy for CPPD, unlike gout.)
2. RA vs OA — RA spares DIP, symmetric small-joint, warmth + soft swelling, marginal erosions. OA involves DIP (vs RA spares DIP), "bony swellings" + crepitus, osteophytes + joint-space narrowing.
3. DM vs PM vs IBM — DM has rash (Gottron's pathognomonic, heliotrope); PM has NO rash (the key DM-vs-PM split); IBM = males >50, both proximal AND distal weakness, does NOT respond to steroids.
4. GPA vs EGPA vs MPA (ANCA vasculitides) — GPA: cANCA/anti-PR3 (>95%), ENT + lung + kidney. EGPA: pANCA/anti-MPO + asthma + eosinophilia. MPA: pANCA/anti-MPO, pauci-immune GN, distinguished from EGPA by NO asthma/eosinophilia.
5. Primary vs Secondary Raynaud's — Primary (good signs): teen/early-20s onset, stable, familial, normal capillaries, ANA−. Secondary (bad signs): male, ≥35 yr onset, increasingly severe, no FH, abnormal capillaries, ANA+/ENA+ (10–15% progress to defined CTD).

Buzzword → answer (the vignette reflex)

• Nikolsky sign +, flaccid blisters that shear, cleavage at stratum corneum, child <5 y → Staphylococcal scalded skin syndrome (SSSS; Rx flucloxacillin)
• TSST-1 superantigen, desquamation of palms + soles, tampon → Toxic shock syndrome (S. aureus)
• Strawberry tongue → raspberry tongue, circumoral pallor, blanching rash → Scarlet fever (erythrogenic toxin)
• Rich focus rupturing into basal cisterns, thick basal exudate, cranial-nerve palsies → Tuberculous meningitis
• India ink encapsulated yeast, "soap bubble" lesions, raised opening pressure → Cryptococcal meningitis (HIV CD4 <100)
• "Owl's eye" intranuclear inclusions, "pizza-pie" retinitis → CMV
• Heterophile antibody (Monospot) +, atypical lymphocytes, splenomegaly → EBV infectious mononucleosis
• Silver (Gomori methenamine) stain cup/boat-shaped cysts, diffuse ground-glass → Pneumocystis jirovecii pneumonia (PCP)
• Multiple ring-enhancing lesions in AIDS + serum anti-Toxo IgG → Cerebral toxoplasmosis
• Foamy histiocytes packed with acid-fast bacilli, CD4 <50 → Mycobacterium avium complex (MAC)
• "Blue beads" at apex of enterocytes, modified acid-fast oocysts in stool → Cryptosporidium parvum
• Halo sign + crescent sign, galactomannan, prolonged neutropenia → Invasive pulmonary aspergillosis
• Faget sign (relative bradycardia) + rose spots on abdomen, return from India → Enteric fever (typhoid)
• Eschar / tache noire at bite site, African game park → Tick typhus (Rickettsia)
• Councilman bodies in liver + Faget's sign + coffee-ground vomit → Yellow fever
• "Break-bone fever", saddleback (biphasic) fever, retro-orbital pain → Dengue
• Katayama fever + terminal haematuria, freshwater Africa → Schistosoma haematobium
• Cytoadherence "knobs" → sequestration, worst prognosis → P. falciparum
• Hydrophobia + tingling at bite site, dog bite → Rabies
• Risus sardonicus, trismus (lockjaw), tetanospasmin → Tetanus
• Descending flaccid paralysis, SNARE-protein cleavage (honey/canning) → Botulism

Bug → disease → drug

Criteria / staging / scores at a glance

• Fever definition — >37.2 °C before noon, >37.7 °C after noon.
• Classic FUO — >38.3 °C (101 °F) on several occasions, >3 weeks, no diagnosis despite 1 week inpatient OR 3 outpatient visits. Categories: Classic · Nosocomial · Neutropenic (neutrophils <500/µL) · HIV (>4 wk outpatient OR >3 days inpatient).
• CSF in meningitis — Bacterial: turbid, WBC ≥1000 PMN, protein ↑ (>1 g/L), glucose low, LDH raised. Viral: clear, <100 lymphocytes, glucose usually normal, LDH not raised. TB/fungal: lymphocytes, low glucose, high protein. Normal opening pressure <20 cm, WBC <5, protein <0.5 g/L, CSF:serum glucose <66%.
• Neutropenia — ANC <500/µL = serious-infection risk; <100/µL = severe. Febrile neutropenia = >38.3 °C single OR >38 °C sustained >1 h; high-risk = <100 for >7 days. ANC = WBC × (% neutrophils + % bands).
• HIV CD4 / OI risk — >500 none · 200–500 pneumococcus/TB/oral candida/Kaposi/VZV-HSV/molluscum · 100–200 PCP/PML(JCV)/histo/cocci · 50–100 toxo/crypto/cryptosporidium/CMV · <50 MAC + tissue-invasive CMV. CMV retinitis ~CD4 10; general OI once <50/µL.
• WHO severe malaria (P. falciparum) — cerebral malaria, severe anaemia, DIC, blackwater fever, hypoglycaemia, lactic acidosis, renal failure (ATN), algid malaria, pulmonary oedema/ARDS; + hyperpyrexia, hyperparasitaemia, jaundice, prostration.
• Dengue course — Febrile d1–3 · Critical d4–6 (platelet nadir, haematocrit peak) · Recovery d7–10 (fluid-overload risk). DHF/DSS needs ≥2 sequential infections with different serotypes; mortality up to 44%.
• EM / SJS / TEN spectrum — EM minor/major = typical targets (HSV, Mycoplasma), does NOT → TEN · SJS <10% BSA · overlap 10–30% · TEN >30% detachment; SJS/TEN = Type IV, drug-triggered (NSAIDs, antibiotics, antiepileptics).
• Immunodeficiency → pathogen — Humoral (myeloma/CLL/AIDS) → encapsulated (S. pneumoniae, H. influenzae) · T-cell (HIV/lymphoma/steroids) → intracellular + fungal · Neutropenia → Gram-negatives/Candida/Aspergillus · Complement → S. pneumoniae/Neisseria · Asplenia → encapsulated + Plasmodium.
• Herpesvirus family — Alpha: HSV-1, HSV-2, VZV · Beta: CMV, HHV6, HHV7 · Gamma: EBV (HHV4), KSHV (HHV8).
• Malaria species — falciparum variable (48 or 24 h, malignant tertian, recrudescence) · vivax/ovale 48 h tertian (relapse, hypnozoites → primaquine) · malariae 72 h quartan (longest) · knowlesi 24 h (shortest).
• Antimicrobial MOA — cell wall: β-lactams + glycopeptides · folate: trimethoprim/sulphonamides · DNA gyrase: quinolones · RNA polymerase: rifampicin · 50S: macrolides/chloramphenicol/lincosamides · 30S: tetracyclines/aminoglycosides.
• Stewardship (Start Smart Then Focus) — no antibiotics without evidence of bacterial infection; treat within 1 h for severe sepsis; review at 48–72 h → STOP / IV-to-oral / change / continue / OPAT.
• Hartford nomogram (aminoglycosides) — single daily dose 5–7 mg/kg (7 at RFH); level 6–14 h after dose; interval Q24 / Q36 / Q48.
• Egyptian schedule — BCG birth; OPV birth/2/4/6/9/18 mo; DTwP 2/4/6/18 mo; Hep B 2/4/6 mo; MMR 12/18 mo; MenAC 3/6/12/15 y.
• UK schedule — 5-in-1 (DTaP/IPV/Hib) at 2/3/4 mo; MMR 1st at 13 mo, 2nd at 3–5 y; Td/IPV at 13–18 y; HPV boys+girls 12–13 y.

Discriminators that decide questions

1. Cerebral toxoplasmosis vs Primary CNS lymphoma — Toxo = multiple ring-enhancing lesions + serum anti-Toxoplasma IgG, headache a constant finding. Lymphoma = solitary lesion + CSF EBV, EBV-associated diffuse large B-cell.
2. CMV vs EBV mononucleosis — CMV = mononucleosis without pharyngeal exudate or heterophile antibodies. EBV = tonsillitis + exudate + positive Monospot (heterophile antibody).
3. Malaria relapse vs recrudescence — Relapse = P. vivax/ovale from dormant hypnozoites (needs primaquine). Recrudescence = P. falciparum from partial/incomplete treatment.
4. Bacterial vs viral meningitis (CSF) — Bacterial = turbid, ≥1000 PMN, low glucose, raised LDH. Viral = clear, <100 lymphocytes, normal glucose, LDH not raised.
5. OPV (Sabin) vs IPV (Salk) — OPV Sabin = live attenuated polio (may revert to wild-type, CI in immunosuppression/pregnancy). IPV Salk = killed polio (safe in immunocompromised).

Buzzword → answer (the vignette reflex)

• Left supraclavicular node (Virchow's) = Troisier's sign → gastric adenocarcinoma
• Krukenberg tumour (ovarian met, transperitoneal spread) → gastric adenocarcinoma
• Sister Mary Joseph nodule (umbilical) / Blumer's shelf (rectal shelf) → gastric adenocarcinoma
• Free air under diaphragm on erect AXR + board-like rigidity → perforated peptic ulcer
• Succussion splash + projectile, non-bile-stained vomiting of old food → gastric outlet obstruction (pyloric stenosis)
• "Herald bleed" after AAA repair / aortic graft → aorto-enteric fistula
• Whipple's triad (hypoglycaemia sx + low glucose + relief on glucose) → insulinoma
• 4D — Diabetes + Dermatitis (necrolytic migratory erythema) + DVT + Depression → glucagonoma
• WDHA — Watery Diarrhoea despite fasting + Hypokalaemia + Achlorhydria → VIPoma (Verner-Morrison)
• Flushing + right-sided valvular heart fibrosis + wheeze → carcinoid syndrome
• Reheated/improperly cooked fried rice → Bacillus cereus (preformed emetic toxin, 1–6 h)
• Profuse rice-water stool → cholera (Vibrio)
• Reversal of hot/cold sensation after reef fish (grouper, barracuda, red snapper) → ciguatera
• Flushing + urticaria minutes after tuna / mackerel → scombroid (histamine)
• Ground beef → bloody diarrhoea in the absence of fever → HUS → Shiga-toxin E. coli (STEC/EHEC O157:H7)
• Home-canned food + descending paralysis + visual disturbance → botulism

Endoscopy / histology / imaging → diagnosis

Criteria / staging / scores at a glance

Oesophagus

• LA classification (reflux oesophagitis): A = break ≤5 mm; B = break >5 mm; C = continuous between ≥2 folds, <75% circumference; D = ≥75% circumference (Grade B most prevalent).
• Corrosive CT grades (A–C): A homogenous enhancement → resolves; B-I wall oedema + mediastinal stranding → stricture 20%; B-II external enhancement + internal necrotic mucosa → stricture 80%; C absent post-contrast enhancement → perforation.
• Phases of lye injury: acute necrotic 1–4 days → ulceration-granulation from 3–5 days (lasts 10–12 days, oesophagus weakest) → cicatrization/scarring from 3rd week.
• Grade-based corrosive mgmt: A oral / first aid only; B TPN or tube + endoscopy after 3 wks ± dilatation → stent → surgery; B-II surgery; C jejunostomy + surgery.
• Perforation mortality: overall ~20%, Boerhaave (spontaneous) ~36%, instrumental ~18%, primary emergency repair ~12% (cervical lowest, thoracic highest; delay >24 h ↑ mortality).
• Perforation surgery by site: cervical → left neck; upper/mid-thoracic → right thoracotomy; lower/distal → left thoracotomy (7th ICS) or transhiatal; <24 h primary anastomosis, >24 h diversion (spit fistula + staple stomach).
• Oesophagus regions from incisor: cervical 15–18 cm, upper thoracic 18–24, midthoracic 24–32, lower thoracic 32–40 cm.
• AJCC TNM (oesophageal ca): Tis = HGD; T1 muscularis mucosa (a) / submucosa (b); T2 muscularis propria; T3 adventitia; T4a resectable / T4b unresectable; N1/N2/N3 = 1–2 / 3–6 / ≥7 nodes; M1 = distant met. (SCC stage groupings add grade + location; Stage IV = any M1.)

Stomach / gastritis / PUD

• Updated Sydney system (2001): classifies gastritis by aetiology, topography, morphology.
• H. pylori eradication (regimen titles): bismuth quadruple = current first line; clarithromycin- & levofloxacin-based dropped (resistance); salvage; high-dose dual therapy (HDDT).
• Test-and-treat H. pylori (ACG 2017): active/past PUD, MALT lymphoma, post-EMR early gastric ca, dyspepsia <55 without alarm features, long-term low-dose aspirin, chronic NSAIDs, unexplained IDA, ITP.
• Bleeding severity in PU: microscopic → mild (granulation tissue) → moderate (small vessel) → severe (gastroduodenal artery — usually fatal).
• Stages of perforated PU: pathology = perforation → chemical peritonitis → septic peritonitis; clinical = shock → lucid interval (obliterated liver dullness) → septic peritonitis.
• Forrest (PU rebleed risk): Ia jet arterial 90%; Ib oozing 50%; IIa visible vessel 25–30%; IIb adherent clot 10–20%; IIc black spot 7–10%; III clean base 3–5%.

Gastric cancer

• Bormann gross (I–IV): I polypoid, II fungating, III ulcerated, IV infiltrating (linitis plastica); III & IV incurable.
• Depth: Early = mucosa/submucosa ± LN (T1; 5-yr ~90%) vs Advanced = into muscularis (has 4 Bormann types).
• TNM (gastric): T1 lamina propria/submucosa; T2 muscularis propria/subserosa; T3 penetrates serosa; T4 adjacent structures; N1 perigastric, N2 left gastric artery, N3 common hepatic/splenic/coeliac; M1 distant.
• LN dissection: D1 perigastric (N1); D2 = D1+N2 (standard curative); D3 = D2+N3.
• Stage vs 5-yr survival: T1N0M0 95+%; T1N1M0 70–80%; T2N1M0 45–50%; T3N2M0 15–25%; M1 0–10% (key prognostic factors = depth of invasion + LN involvement).
• IGCLC CDH1 testing: ≥2 diffuse gastric ca in 1st/2nd-degree relatives with ≥1 before age 50, OR ≥3 relatives at any age.

Neuroendocrine tumours

• MEN-1: pancreatic (insulinoma/gastrinoma/VIPoma) + pituitary adenoma + parathyroid hyperplasia. MEN-2A/2B: medullary thyroid ca (100%) + phaeo (50%); MEN-2B adds marfanoid habitus (80%) + mucosal neuromata (>95%).
• Whipple's triad (insulinoma): hypoglycaemia symptoms + low glucose at symptom time + resolution on glucose.
• Glucagonoma 4D: Diabetes, Dermatitis (necrolytic migratory erythema), DVT, Depression.
• VIPoma WDHA: Watery Diarrhoea (despite fasting), Hypokalaemia, Achlorhydria.
• Somatostatinoma inhibitory pentad: diabetes, cholelithiasis/gallstones, weight loss, steatorrhoea, hypochlorhydria.
• Chromogranin A = general NET marker (positive = a NET somewhere).

UGI bleeding

• Causes by site: oesophageal = Mallory-Weiss, varices, oesophagitis, malignancy, AEF; gastric = PUD, varices, malignancy, gastritis, Dieulafoy; duodenal = PUD, ectopic varices, duodenitis, malignancy.
• Transfusion threshold: Hb 8.5 if ischaemic heart disease; 7.5 if otherwise well. Orthostatic drop = acute loss of ≥20% blood volume; shock signs = HR >100, SBP <90.

Functional / bowel

• Rome IV IBS: recurrent abdominal pain ≥1 day/week for 3 months (onset ≥6 months prior) + ≥2 of: related to defecation, change in stool frequency, change in stool form. (IBS-D = >25% Bristol 6–7 and <25% Bristol 1–2.)
• IBS subtypes (Bristol): IBS-C hard/lumpy ≥25% & loose <25%; IBS-D loose/watery ≥25% & hard <25%; mixed both ≥25%; unsubtyped.
• Constipation criteria: ≥2 of — <3 motions/week, incomplete evacuation, straining >25% of time, manual/digital evacuation. (Colon transit time normally 20–72 h.)
• Bristol stool chart: 1 hard lumps (severe constipation) → 3–4 normal → 7 liquid (severe diarrhoea).
• Chronic diarrhoea types: osmotic (improves fasting, stool osmotic gap >50 mOsm/L); malabsorption (weight loss + good appetite, high faecal fat); secretory (large watery, normal gap); inflammatory (fever, bloody, tenesmus); motility.
• BINDS (investigate acute diarrhoea): Bloody, Immunosuppressed, Nosocomial, Dehydration, Severe >10 days.
• Foodborne mechanisms: preformed enterotoxin (S. aureus, B. cereus — onset 1–6 h, vomiting); enterotoxin made in gut (C. perfringens, ETEC/STEC, cholera — >1 day, watery/bloody); bacterial invasion (Campylobacter, non-typhoidal Salmonella, Listeria).

Nutrition

• Malnutrition criteria: ≥2 of — low energy intake, weight loss, loss of muscle mass, loss of subcut fat, fluid accumulation, reduced hand-grip strength.
• NRS-2002: initial screen positive if BMI <20.5 / recent weight loss / reduced intake / severely ill; total ≥3 = at-risk; if age ≥70 add 1.
• Refeeding syndrome risk: high (≥1) — BMI <16, weight loss >15% in 3–6 mo, little/no intake >10 days, low K/PO₄/Mg; moderate (≥2) — BMI <18.5, weight loss >10% in 3–6 mo, no intake >5 days, alcohol/drug misuse. Onset usually within first 4 days of feeding; hypophosphataemia drives it.

Discriminators that decide questions

1. Gastric ulcer vs duodenal ulcer: GU pain provoked by food, blood group A, ~80% H. pylori, can be malignant → biopsy, recurs 40–60%/2 yr; DU pain relieved by food, blood group O, up to 95% H. pylori, almost always benign → no biopsy, recurs 95% (50% in 6–8 months). GU = 25%, DU = 75% (4× as common).
2. H. pylori vs autoimmune gastritis: H. pylori = antrum, neutrophils, normal/↑ acid, normal/↓ gastrin, anti-Hp Ab; autoimmune = body only (spares antrum), lymphocytes, ↓ acid (achlorhydria), ↑ gastrin, anti-parietal/intrinsic-factor Ab, neuroendocrine hyperplasia → carcinoid risk.
3. Oesophageal SCC vs adenocarcinoma: SCC = commonest worldwide, middle third, risks alcohol+tobacco / Plummer-Vinson / achalasia / caustic / HPV 16,18; adeno = commonest in US/West, lower third, risks Barrett's / GERD / hiatal hernia / Zollinger-Ellison / obesity.
4. Benign vs malignant gastric ulcer (endoscopic): benign = smooth, regular, rounded edge, flat smooth base, radiating folds; malignant = irregular overhanging margins, ulcerated mass into lumen, nodular/irregular folds.
5. Osmotic vs secretory diarrhoea: osmotic improves with fasting, stool osmotic gap >50 mOsm/L; secretory = large watery stool, normal osmotic gap (persists despite fasting).

Buzzword → answer (the vignette reflex)

• Pseudopolyps / lead-pipe colon on barium (loss of haustration) → Ulcerative Colitis
• Backwash ileitis (≤ 25 cm of ileocaecal valve) → Ulcerative Colitis
• Skip lesions + cobblestone + string sign on barium + creeping fat → Crohn's Disease
• Non-caseating sarcoid-like granulomas / transmural inflammation → Crohn's Disease
• pANCA positive → UC (over CD); ASCA positive, pANCA negative → CD
• Colon "carpeted" with hundreds–thousands of polyps, APC on 5q21 → FAP
• Right colon/proximal, mucinous, lymphocytic infiltrate, MSI-H, younger age → Lynch (HNPCC)
• Mucocutaneous pigmentation (lips/buccal/palms/soles) + arborising smooth-muscle-core hamartoma → Peutz-Jeghers
• Scalloping of the liver capsule on CT → Pseudomyxoma Peritonei (pathognomonic)
• Cannonball hepatic nodules / apple-core sign on barium enema → Colorectal Cancer
• Kulchitsky cells of crypts of Lieberkühn, at the tip of the appendix → Appendiceal Carcinoid
• Periumbilical pain migrating to RIF / McBurney's point → Acute Appendicitis
• Painless bright-red bleeding, dripping/squirting on defecation → Internal Haemorrhoids
• Posterior-midline linear ulcer, "more pain, less bleeding" + sentinel pile → Anal Fissure
• Midline pits ~5 cm posterior to anus + protruding hairs ("jeep disease") → Pilonidal Sinus
• Painless bleeding + currant-jelly stool in a child, Tc-99m pertechnetate scan → Meckel's Diverticulum
• Saint's triad = diverticulosis + hiatus hernia + gallstones → Diverticular Disease

Endoscopy / histology / imaging → diagnosis

Criteria / staging / scores at a glance

• Truelove & Witts (severe UC): > 6 stools/day + blood +++, fever > 37.5 °C, HR > 90, ESR > 30 mm/hr, Hb < 10 g/dL, albumin < 30 g/L. (Mild < 4/day, Moderate 4–6, Severe > 6.)
• Massive LGIB: ≥ 4 U blood/24 h, instability + shock, Hb ≤ 6 g/dL, bleeding > 3 days, rebleed within 1 week.
• UC definitive path: diffuse, continuous from rectum, no skip lesions, no deep fissures, no transmural sinus tracts/granulomas.
• CD definitive path: terminal-ileum inflammation, fistulas/sinus tracts, serositis, fat-wrapping, transmural lymphoid aggregates, non-necrotising granulomas, skip lesions, linear ulcers, cobblestone.
• Hinchey (complicated diverticulitis): I pericolic/mesenteric abscess · II pelvic/retroperitoneal abscess · III purulent peritonitis · IV faecal peritonitis. (I–II → drainage; III–IV → surgery.)
• Internal haemorrhoid grades: I enlarged, no prolapse (bleeding only) · II prolapse reduces spontaneously · III needs manual reduction · IV irreducible.
• Parks (anal fistula): 1 Intersphincteric (commonest) · 2 Transsphincteric (2nd) · 3 Suprasphincteric · 4 Extrasphincteric (NOT cryptoglandular).
• St James's MRI (anal fistula): 0 normal · 1 simple intersphincteric · 2 intersphincteric + abscess/track · 3 transsphincteric · 4 transsphincteric + abscess/track in ischiorectal fossa · 5 supralevator/translevator.
• Goodsall's rule: anterior to transverse anal line → straight radial tract; posterior → curved, opens midline posteriorly. Exceptions (complex): anterior openings > 3 cm from margin, or multiple openings.
• Montreal — UC extent: E1 proctitis · E2 left-sided (to splenic flexure) · E3 extensive/pancolitis. CD: Age A1 ≤ 16, A2 17–40, A3 > 40 · Location L1 terminal ileum, L2 colon, L3 ileocolon, L4 upper GI · Behaviour B1 non-stricturing/non-penetrating, B2 stricturing, B3 penetrating, "p" = perianal.
• Toxic megacolon: colon > 5.5 cm (X-ray > 5 cm, thin-walled gas-filled with mucosal islands); transverse colon; mortality 15–25%; urgent subtotal colectomy + Brooke if not resolved in 48 h.
• TNM (CRC) — T: Tis in situ · T1 submucosa · T2 muscularis propria · T3 subserosa · T4 visceral peritoneum. N: N0 none · N1 1–3 nodes (N1a 1, N1b 2–3, N1c tumour deposits, no +ve nodes) · N2 ≥ 4 (N2a 4–6, N2b ≥ 7) · N3 high-tie nodes. M: M1a one organ · M1b > 1 organ/peritoneum.
• pT layers (inner→outer): mucosa → submucosa → muscularis propria → subserosa → peritoneal elastic lamina → mesothelium. pT1 submucosa · pT2 MP · pT3 subserosa · pT4 perforates peritoneum.
• Stage grouping: 0 Tis (polyp removal) · I T1/T2 N0 (surgery) · IIA T3N0, IIB T4aN0, IIC T4bN0 (surgery) · III any node+ (surgery + adjuvant chemo) · IVA M1a, IVB M1b (chemo + biologics ± rectal RT).
• Modified Dukes' + 5-yr survival: A (T1N0) 95% · B1 (T2N0) ~85% · B2 (T3/T4N0, through MP) 80% · C1 (node+, apical node −) ~60% · C2 (apical node +) ~30% · D (M1) 5%.
• Rectal cancer by TNM: T1N0 → local excision; T1–2N0 → transabdominal; T3N0 or any T + N1/N2 → pre-op chemoradiotherapy → surgery.
• Anterior resection by height (from anal verge): ~11–15 cm (upper 3rd, above peritoneal reflection) → AR · ~7–11 cm (middle) → LAR · < 7 cm (lower, pelvic floor) → ULAR.
• Colonic resection by site: caecum/ascending → right hemicolectomy · hepatic flexure → extended right · splenic flexure → extended left · descending → left hemicolectomy · sigmoid → sigmoidectomy. Marginal safe zone = 2 cm.
• Rectal margins: Distal (DRM) + Circumferential (CRM).
• Adenoma malignant potential (highest→lowest): high-grade dysplasia > villous architecture > size (> 2 cm) > multiple. (74% of adenomas < 1 cm → 1% invasive cancer; 35% of adenomas > 2 cm show malignant change.)
• ACG family-history screening: single 1st-degree dx ≥ 60 yr → colonoscopy every 10 yr from age 45; single 1st-degree < 60 yr OR ≥ 2 relatives → age 40 (or 10 yr before youngest's dx), repeat every 5 yr.
• UK National Screening: age 50–74 offered FIT; positive → colonoscopy; negative → repeat every 2 yr.
• Average-risk screening: start FOBT (gFOBT guaiac needs 3-day red-meat elimination, vit C < 250 mg/day, no NSAIDs 7 days; FIT uses antibodies to human Hb, no diet restriction, very good sensitivity; annual US / 2-yearly UK / 3-yearly Holland); starts age 50 or 60.
• Anal cancer risk: HPV-16 very high (18/31/33/35 moderate); HIV; tobacco 5-fold; benign anal pathology (fistula/fissure/haemorrhoid) does NOT increase risk.
• Appendiceal perforation risk: extremes of age, immunosuppression, diabetes, previous abdominal surgery.
• Alvarado (MANTRELS, /10): Migratory RIF pain 1 · Anorexia 1 · Nausea/vomiting 1 · Tenderness RIF 2 · Rebound 1 · Elevated temp 1 · Leukocytosis (WBC ≥ 10×10⁹/L) 2 · Shift to left 1. → < 3 low (discharge/observe); 4–6 imaging; ≥ 7 appendicectomy.
• Pediatric Appendicitis Score (PAS, /10): RLQ tenderness 2 · cough/hopping/percussion RLQ 2 · all others 1. → 1–3 negative; 4–7 further testing; 8–10 positive.
• AIR score: adds CRP to WBC/neutrophilia; better than Alvarado in adults.
• ATLS shock class: I < 750 mL / < 15% / HR < 100 · II 750–1500 / 15–30% / HR > 100 (orthostatic) · III 1500–2000 / 30–40% / HR > 120 (reduced SBP, UO 10–20) · IV > 2000 / > 40% / HR > 140 (supine hypotension, UO < 10).
• Ileal pouch configs: J (2 loops, most popular, linear stapler) · S (3 loops, long spout → evacuation difficulty) · W (4 loops, larger reservoir → less frequency). Pouch 10–20 cm.
• Ileostomy: end Brooke's spout ≥ 4 cm above skin, acts in 48 h; Kock = 30 cm reservoir, emptied by catheter.
• Nigro regime (anal SCC): 5-FU + mitomycin (or 5-FU + cisplatin) + RT; obvious residual → APR.
• APR indications: tumour involves pelvic floor / external sphincter, poorly-differentiated low rectal cancer, or < 1 cm from dentate line.
• Vogelgram (sporadic adenoma-carcinoma): APC/MCC loss → K-ras → DCC loss → p53 loss → carcinoma. (APC/MCC/DCC/p53 = tumour suppressors; K-ras = oncogene.)
• UC surgery indications (emergency): acute severe colitis failing IV steroids, toxic megacolon/impending perforation, perforation, massive haemorrhage, total obstruction from stricture.

Discriminators that decide questions

1. UC vs Crohn's — UC: mucosa + submucosa only, diffuse/continuous from rectum, pseudopolyps, lead-pipe colon, crypt abscesses, resection curative. Crohn's: transmural, segmental skip lesions, cobblestones/string sign, deep fissures + fistulas + granulomas, perianal disease, resection recurrence common.
2. FAP ("gatekeeper") vs HNPCC/Lynch ("caretaker") — FAP: APC (5q21), adenoma-carcinoma sequence, thousands of typical tubular/villous adenomas, 100% cancer by 40–45. HNPCC: MSH2/MLH1 (MMR → MSI), fewer often-sessile polyps, mucinous adenocarcinoma + lymphocytic infiltrate, right colon/younger.
3. Right- vs left-sided diverticula — Right: Asian, congenital, true (all layers), solitary. Left: Western, acquired, false (pseudodiverticula, pulsion), multiple; sigmoid highest pressure (up to 90 mmHg, 9× normal).
4. Internal vs external haemorrhoids — Internal: above dentate line, transitional + columnar epithelium, painless bright-red bleed. External: below dentate line, squamous epithelium, thrombosed = painful throbbing mass.
5. Blood–stool relation localises the source — mixed with faeces → proximal to sigmoid; on surface of faeces → rectum/anal canal; on toilet paper → anal-skin (fissure, external haemorrhoids); separate from faeces (± mucus, urge to defecate) → rectal cancer, diverticular disease, UC, polyp. (↑ urea:creatinine ratio hints UGIB.)

Buzzword → answer (the vignette reflex)

• Red currant jelly stool → Intussusception (pathognomonic in children <3 yrs)
• Coffee bean / bent inner tube on AXR → Sigmoid volvulus
• Bird's beak / ace of spades on barium enema → Sigmoid volvulus (pathognomonic)
• Coiled spring on contrast/air enema → Intussusception (diagnostic AND therapeutic)
• Target sign on USS/CT → Intussusception
• Caecum displaced to LUQ / comma / kidney bean gas shadow → Caecal volvulus
• Whirlpool / swirl sign on CT (mesenteric vessels wrapped around axis) → volvulus (pathognomonic)
• Free air under diaphragm on erect CXR → perforated hollow viscus → urgent laparotomy
• Restless patient who can't find a comfortable position → Ureteric colic (peritonitis = lies completely still)
• Below and lateral to pubic tubercle → Femoral hernia (inguinal = above + medial)
• Seat belt sign (horizontal abdominal ecchymosis) → mesenteric avulsion / small-bowel injury
• Howship–Romberg sign (medial thigh pain) → Obturator hernia
• Pneumobilia on AXR → gallstone ileus (a cause of SBO)
• Sausage-shaped mass in right hypochondrium → Intussusception

Sign / imaging → diagnosis

Criteria / staging / scores at a glance

• Hernia severity (ascending): Reducible → Irreducible (incarcerated) → Obstructed (lumen occluded, no vascular compromise) → Strangulated (vascular: venous → arterial) → Loss of domain (viscera lost "right of abode").
• Nyhus (groin hernia): I = indirect, normal internal ring · II = indirect, dilated ring, intact posterior wall · III = posterior-wall defect (IIIA direct, IIIB indirect/sliding, IIIC femoral) · IV = recurrent (IVA direct, IVB indirect, IVC femoral, IVD combined).
• Mesh position (Int'l Hernia Collaboration): A Onlay · B Inlay · C Retrorectus · D Preperitoneal · E Intraperitoneal. Primary fascial repair up to 50% recurrence; tension-free mesh 2–10%.
• ABCs of bowel obstruction: A = Adhesions (commonest SBO) · B = Bulge/hernia · C = Cancer (commonest LBO).
• 3/6/9 rule (AXR dilation): small bowel >3 cm · large bowel up to 6 cm · caecum up to 9 cm.
• SBO high-risk findings → operate: significant leucocytosis; lactic acidosis (normal lactate does NOT exclude venous ischaemia); closed loop; bowel dilation >3 cm; pneumatosis intestinalis; free air; mesenteric oedema.
• Gastrografin protocol (adhesional SBO): contrast fails to reach caecum by 24–48 h → conservative will fail → operate.
• Laparotomy indications — obstruction: cause needs surgery (hernia, colonic carcinoma); no improvement on conservative; strangulation/peritonitis; tachycardia + pyrexia + tenderness → operate whatever the cause. Resuscitate FIRST.
• Laparotomy — blunt trauma: haemodynamic instability despite resuscitation; +ve FAST/DPL + instability; peritonism; hollow-viscus injury (free air); diaphragm rupture; expanding/pulsatile retroperitoneal haematoma.
• Laparotomy — penetrating trauma: instability; evisceration; peritonitis; hollow-viscus/vascular injury; gunshot wounds nearly always. Stab = selective (peritoneal signs → laparotomy; stable no signs → local wound exploration).
• Retroperitoneal haematoma zones (blunt): Zone I (central) always explore · Zone II (flank/renal) only if expanding/pulsatile · Zone III (pelvic) do NOT open (releases tamponade).
• 3R trauma framework: Resuscitate (IV upper limbs only, ABC) → Reassess (repeat ABCDE) → Re-evaluate (operate vs observe). Never remove embedded FB in field.
• Caecal vs sigmoid volvulus: sigmoid = >80% of colonic volvulus, older (~5th decade / avg 60), anticlockwise, central; caecal = <40 yrs, women, clockwise, LUQ. Caecal dilation >10 cm + tenderness → impending perforation.
• Incisional hernia: mesh recurrence 2–10% vs up to 50% primary suture; incidence 10–50% after open laparotomy; small defect <3 cm → primary closure.
• Inguinal hernia numbers: 75% of all abdominal hernias are inguinal; 75% of inguinal are indirect.
• Acute abdomen: symptoms <8 days (>8 days probably not lethal); ~1 in 10 presentations is a true surgical emergency.

Discriminators that decide questions

1. SBO vs LBO — vomiting early vs late; distension central vs peripheral; bowel sounds hyperaudible tinkling vs may be absent; main cause adhesions/hernia vs malignancy; adhesions cause SBO but NEVER LBO alone.
2. Indirect vs direct inguinal hernia — lateral vs medial to inferior epigastric vessels; congenital (patent processus vaginalis) vs always acquired; deep-ring occlusion controls the indirect (no bulge on cough) but a direct still bulges medially through Hesselbach's triangle.
3. Inguinal vs femoral hernia — above inguinal ligament + medial to pubic tubercle vs below ligament + lateral to pubic tubercle; femoral has the narrow ring → highest strangulation risk of all hernias; suspect occult femoral in an elderly woman (60–80) with SBO and no prior surgery.
4. Caecal vs sigmoid volvulus — clockwise vs anticlockwise; caecum to LUQ vs sigmoid central; younger women vs older men; caecal has NO endoscopic role → right hemicolectomy, sigmoid = endoscopic detorsion first.
5. Ureteric colic vs peritonitis — colic = restless patient who can't lie still (colicky = hollow-viscus obstruction); peritonitis = lies completely still, guarding/rigidity, silent abdomen. (Richter's hernia is the trap: only the anti-mesenteric wall strangulates → ischaemia WITHOUT obstruction, so stool/flatus continue and presentation is delayed.)

Buzzword → answer (the vignette reflex)

• "Corkscrew collaterals" on angiography → Buerger's disease (young male smoker; claudication + Raynaud's + migratory superficial thrombophlebitis)
• Migratory superficial thrombophlebitis (Trousseau's sign) → thrombophlebitis migrans (paraneoplastic, classically pancreatic adenocarcinoma)
• Abdominal pain "out of proportion" to physical signs → acute mesenteric ischaemia
• Postprandial pain ~30 min after eating + fear of eating + weight loss ("intestinal angina") → chronic mesenteric ischaemia
• Impotence + lower-extremity claudication + buttock wasting → aortoiliac disease (Leriche syndrome)
• "Rocker bottom" deformity (collapsed medial arch) → Charcot foot (disease-defining)
• Champagne bottle sign / atrophie blanche / ankle flare (corona phlebectatica) → chronic venous insufficiency
• Punched-out, intensely painful ulcer, base devoid of granulation, absent pulses, lateral malleolus → arterial ulcer
• Ulcer just proximal to medial malleolus (gaiter's area), irregular sloping white edges → venous ulcer
• Tearing/severe chest pain extending into abdomen, sudden onset → aortic dissection (major RF = hypertension, NOT atherosclerosis)
• Acute abdominal pain + back pain + hypotension (triad) → ruptured AAA (>80% mortality)
• Numbness in webspace between great toe + 2nd toe (deep peroneal nerve) → compartment syndrome (diagnostic)
• Rest pain aggravated by elevation, relieved by hanging leg over bed → critical limb ischaemia
• "Nutmeg" liver → hepatic congestion (right-sided heart failure)

Sign / imaging → diagnosis

Criteria / classifications / scores at a glance

• Wagner (DFU), Grade 0–5: 0 intact skin (impending ulcer); 1 superficial; 2 deep to tendon/bone/ligament; 3 osteomyelitis; 4 gangrene of toes/forefoot; 5 gangrene of entire foot.
• CEAP — C (clinical): C0 no signs; C1 telangiectasia/reticular; C2 varicose veins; C3 oedema; C4A pigmentation+eczema; C4B lipodermatosclerosis+white atrophy; C5 healed ulceration; C6 active ulceration. (E = congenital/primary/secondary; A = anatomical; P = reflux/obstruction.)
• Fontaine (chronic PAD): I asymptomatic; IIa mild claudication; IIb moderate–severe claudication; III ischaemic rest pain; IV ulceration/gangrene.
• Rutherford — chronic PAD (cat 0–6): 0 asymptomatic; 1 mild / 2 moderate / 3 severe claudication; 4 ischaemic rest pain; 5 minor tissue loss; 6 major tissue loss.
• Stanford (dissection): Type A = involves ascending aorta (emergent surgery); Type B = distal to aortic arch.
• Aneurysm classification: aetiology (atherosclerotic/traumatic/congenital/inflammatory/dissecting); structure (true = all 3 layers / false = pseudoaneurysm); shape (fusiform/saccular); site (central/peripheral).
• Vasculitis by vessel size: Large = Takayasu · GCA · Behçet; Medium = PAN · Kawasaki · Buerger; Small = hypersensitivity angiitis.
• Lymphedema stages: 1 reversible, soft pitting, resolves with elevation; 2 irreversible, hard, pitting doesn't resolve with elevation; 3 irreversible (elephantiasis), hard with skin papillomas.
• Wells (DVT): +1 each (active cancer; paralysis/paresis/recent plaster; bedridden ≥3 days or major surgery within 12 wk; localised deep-vein tenderness; entire leg swollen; calf ≥3 cm larger 10 cm below tibial tuberosity; pitting oedema symptomatic leg; collateral superficial veins; prior DVT). −2 if alternative diagnosis at least as likely. <2 low → D-dimer first; ≥2 → compression U/S first.
• Rutherford — acute limb ischaemia: I viable (no sensory/motor, both Doppler audible); IIA marginally threatened (minimal/toe sensory, no motor, arterial ± venous audible); IIB immediately threatened (sensory >toes/rest pain, mild–mod motor, arterial inaudible); III irreversible (profound/anaesthetic sensory, profound motor rigor, arterial + venous both inaudible).
• 6 Ps of ALI: Pain, Pallor, Pulselessness, Paraesthesia, Paralysis, Poikilothermia.
• ABI: >1.2 noncompressible/calcified (DM); 1.0–1.2 normal; 0.5–0.9 intermittent claudication; 0.1–0.4 critical limb ischaemia. CLI = ankle pressure <70 mmHg / toe pressure <50 mmHg. Trauma: ABI <0.9 → CTA.
• Hard vs soft signs (vascular trauma): hard (arterial/pulsatile bleeding, persistent haemorrhage + shock, expanding/pulsatile haematoma, thrill, bruit, absent pulse/distal ischaemia) → immediate OR; soft (small stable haematoma, related nerve injury, unexplained hypotension, prior haemorrhage, proximity to major vessel, diminished/unequal pulses) → further investigation.
• Virchow's triad: endothelial dysfunction/injury + altered blood flow (stasis or turbulence) + hypercoagulability.
• Exudate vs transudate: protein >3 g% vs <3 g%; specific gravity >1015 vs <1015; fibrinogen high (clots) vs none; cloudy vs clear; ↑ vascular permeability vs ↑ hydrostatic/↓ osmotic.
• Compression stocking classes: Class I 18–21 mmHg (minor varicosities/prevention); Class II 26–34 mmHg (uncomplicated varicose veins); Class III >34 mmHg (complicated varicose veins/venous ulcers). Contraindicated in PAD + cardiac failure; min ABPI >0.8 for safe compression.
• AAA screening & rupture risk (SVS): screen men ≥65 (all), men ≥55 (+FHx), women ≥65 (+FHx or personal smoking history). Rupture risk by size: 3–4 cm <0.5% → 4–5 cm 0.5–5% → 5–6 cm 3–15% → 6–7 cm 10–20% → 7–8 cm 20–40% → >8 cm 30–50%. Elective repair: men ≥5.5 cm; women 4.5–5.4 cm; expansion >1 cm/year; saccular; symptomatic; atypical (dissecting, mycotic pseudoaneurysm).
• Aneurysm elective-repair size thresholds (from disease entries): iliac >3.5 cm; splenic >2.5 cm; renal >2 cm (>2 cm in childbearing-age women); popliteal >2.0 cm (or thromboembolic); femoral >2.5 cm; pseudoaneurysm >2.5 cm → U/S-guided thrombin injection.

Discriminators that decide questions

1. Arterial vs venous ulcer — Arterial: punched-out margin, intensely painful, base devoid of granulation, absent pulses, lateral malleolus/dorsum/distal digits, AVOID compression. Venous: just proximal to medial malleolus (gaiter's area), irregular sloping white edges, slough + exudate, surrounding lipodermatosclerosis, Class III compression = mainstay.
2. Embolic vs thrombotic ALI — Embolic: sudden onset, no claudication history, no bruit (except aneurysm site), clinical diagnosis. Thrombotic: onset over hours/days, prior claudication history, bruit across trunk, needs angiography.
3. Dry vs moist gangrene — Dry: arterial occlusion + patent veins, line of demarcation / conical stump, slow putrefaction + mild toxaemia, no sepsis risk. Moist: occlusion of BOTH artery AND vein, poor demarcation / no line of separation, rapid putrefaction + severe toxaemia.
4. Lipoedema vs lymphoedema — Lipoedema: always bilateral, symmetrical, feet/toe sparing, Stemmer's sign negative. Lymphoedema: involves dorsum of foot, Stemmer's sign positive.
5. Phlegmasia (venous) vs acute arterial ischaemia — Phlegmasia cerulea dolens: cyanotic + swollen. Acute arterial ischaemia: pale + cold.

Buzzword → answer (the vignette reflex)

• Dinner-fork deformity / FOOSH with wrist EXTENDED → Colles' fracture (distal radius, DORSAL angulation, extra-articular)
• Garden-spade deformity / fall onto FLEXED wrist → Smith's fracture (distal radius, VOLAR angulation)
• Anatomic snuffbox tenderness + FOOSH → Scaphoid fracture (retrograde supply → AVN/non-union; more proximal # = higher risk)
• Pain OUT OF PROPORTION + pain on PASSIVE stretch → Compartment syndrome (emergency fasciotomy)
• Crescent sign on X-ray → Osteonecrosis / AVN (earliest X-ray sign; MRI = gold standard)
• Saddle anaesthesia + BILATERAL sciatica + bowel/bladder incontinence → Cauda equina syndrome (emergency; MRI)
• Bone pain WORSE AT NIGHT, relieved by salicylates → Osteoid osteoma
• Distal 1/3 humeral SPIRAL # + wrist/finger drop → Holstein-Lewis (radial nerve at risk)
• Simmonds'/Thompson's +ve (squeeze calf, no plantarflexion) → Achilles rupture
• Finkelstein +ve / radial-sided wrist pain → De Quervain's tenosynovitis (1st dorsal extensor compartment)
• Tinel's/Phalen's +ve, numb radial 3½ digits, thenar wasting → Carpal tunnel syndrome (median nerve)
• Kanavel's 4 signs → Pyogenic flexor tenosynovitis
• Prominent acromion + empty glenoid, arm held in external rotation → Anterior shoulder dislocation (check AXILLARY nerve)
• 'Lover's fracture' — heel pain after fall from height → Calcaneus fracture (CT essential)
• Sequestrum + involucrum → (Haematogenous) osteomyelitis — pathological hallmarks
• Sunburst periosteal reaction → Osteosarcoma

Fracture eponym / sign → injury

Criteria / classifications / scores at a glance

• Four R's (fracture mgmt order): Resuscitation → Reduction → Immobilisation → Rehabilitation
• ATLS primary survey (ABCDE): Airway + C-spine · Breathing · Circulation + haemorrhage control · Disability · Exposure/environment
• AMPLE history: Allergies · Medications · Past medical hx · Last meal · Events surrounding injury
• Apley's exam: Look · Feel · Move · Special tests (+ joint above AND joint below)
• RICE (acute soft-tissue / sprain): Rest · Ice · Compression · Elevation
• Edinburgh position (Boxer's / 5th MC neck #): wrist extended 20°, MCP flexed 60–70°, IPs in extension
• Gustilo (open #): I ≤1 cm, minimal contamination · II 1–10 cm, moderate soft-tissue injury · IIIA usually >10 cm, high energy/contaminated, ADEQUATE tissue for flap · IIIB extensive PERIOSTEAL stripping → needs plastic cover · IIIC associated vascular injury needing repair. Farm injuries automatically ≥IIIA.
• Mirels' score (MBD impending #): >8 → consider prophylactic stabilisation (four components not individually detailed in deck)
• Compartment-pressure thresholds: absolute >40 mmHg, OR delta (diastolic BP − compartment) <30 mmHg; diagnosis mainly clinical
• Kocher's NEWT (paediatric septic arthritis): Non-weight-bearing · Elevated ESR · White-cell count elevated · Temperature (fever)
• MSIS 2011 definite PJI: EITHER major (sinus tract to prosthesis, OR pathogen in ≥2 separate samples) OR 4 of 6 minor (↑ESR + CRP; ↑synovial leukocytes; ↑synovial PMN%; purulence; 1 positive periprosthetic culture; >5 neutrophils/HPF in 5 HPFs at ×400)
• DAIR (early PJI <3 wk): Debridement · Antibiotics · Implant Retention; absolute cut-off 3 weeks from symptom onset
• One- vs two-stage PJI revision: one-stage if organism KNOWN (new implant + antibiotic-loaded cement, 3 peri-op doses) · two-stage if UNKNOWN — stage 1: remove implant + debride + odd-number samples (3/5/7) + antibiotic-cement spacer + 6 wk antibiotics → stage 2: remove spacer + new implant, no antibiotics
• 5th MT base zones: Zone 1 Avulsion/Dancer's/Pseudo-Jones (tuberosity, peroneus brevis) · Zone 2 JONES # (metaphyseal–diaphyseal junction, watershed → non-union) · Zone 3 proximal diaphyseal stress # in athletes
• Cobb's angle (scoliosis): <30° non-op (posture/strengthening, Milwaukee brace) · >30° or expected to progress → operative correction + rebalancing
• Hyperkyphosis angle: >50° → operative correction + spinal fixation
• Synovial fluid: Normal = clear yellow, high viscosity, few WBC · Septic = purulent, LOW viscosity, WBC >10,000/mm³, LOW glucose, +ve bacteriology · Gout = cloudy, URATE crystals · Pseudogout = cloudy, PYROPHOSPHATE crystals
• Arthroplasty complications (5): PJI · dislocation · limb-length discrepancy · osteolysis · polyethylene wear
• Fracture description (imaging): shape by line — transverse / oblique / spiral / longitudinal; angulation medial = valgus, lateral = varus; overriding + foreshortening = bayonet apposition; children — bowing/plastic, torus/buckle, greenstick
• Bankart (shoulder instability): I cartilaginous (antero-inferior labrum/IGHL avulsion) · II bony (+ antero-inferior glenoid rim #); paired with Hill-Sachs (postero-lateral humeral head impaction) in anterior dislocation
• Modic end-plate (MRI): I oedema (low T1, bright T2) · II fatty (bright T1 & T2) · III sclerotic (low T1 & T2)
• Meyerding (spondylolisthesis): graded I–IV by % vertebral slippage
• Meniscal signal grades (MRI): 1 globular (asymptomatic) · 2 linear not reaching surface · 3 reaches one articular surface (= tear) · 4 complex, both surfaces
• Sacroiliitis MRI phases: oedema (STIR bright, active, most sensitive) → fatty (bright T1/T2) → sclerotic (low T1/T2, seen on plain X-ray)

Discriminators that decide questions

1. Colles' vs Smith's — both distal radius, extra-articular: Colles' = DORSAL angulation (FOOSH, wrist extended, dinner fork); Smith's = VOLAR angulation (fall on flexed wrist, garden spade, always operative/ORIF).
2. Monteggia vs Galeazzi — Monteggia = proximal 1/3 ULNA # + radial head dislocation (easily missed); Galeazzi = distal 1/3 RADIUS # + DRUJ dislocation, 3× as common, 'fracture of necessity' (always surgical).
3. Non-union: hypertrophic vs atrophic — hypertrophic = good blood supply, flared ends + abundant callus (mechanical cause) → STABILISATION; atrophic = poor vascularity + too-rigid fixation, withered ends → BIOLOGICAL enhancement (bone graft).
4. NOF #: intracapsular vs extracapsular — intracapsular (femoral head, subcapital, trans-cervical) = high AVN/non-union risk (medial femoral circumflex supply disrupted); extracapsular (basicervical, trochanteric) = blood supply preserved, low AVN.
5. Osteosarcoma vs Ewing's — osteosarcoma = most common bone sarcoma, around KNEE (50%)/SHOULDER (25%), peak 2nd decade, metastasises early; Ewing's = 2nd most common, typically DIAPHYSEAL, 80% in first two decades.

Buzzword → answer (the vignette reflex)

• Obsessions → anxiety → compulsions → relief, insight preserved → OCD (SSRI 1st-line; hyperactive CSTC loop)
• Ophthalmoplegia + nystagmus + ataxia + confusion → Wernicke's (thiamine/B1 deficiency; petechial haemorrhages in brain stem)
• Loss of short-term memory after untreated Wernicke's → Korsakoff's (irreversible)
• Disorientation + visual hallucinations + alcohol-withdrawal signs → Delirium tremens (also benzo & cocaine withdrawal)
• Oculogyric crisis + torticollis in young neuroleptic-naïve male → Acute dystonia (high-potency e.g. haloperidol; IM procyclidine)
• Fever + rigidity + altered mental status + autonomic dysfunction + ↑↑CK → NMS (bromocriptine + dantrolene)
• Inner restlessness + compulsion to move, foot stamping/pacing → Akathisia (propranolol)
• Early-morning wakening + diurnal mood variation (worse AM) → biological (melancholic) depression
• QRS >100 ms after overdose → TCA toxicity (antidote sodium bicarbonate)
• Pin-point pupils + respiratory depression + sedation/coma → Opioid overdose (naloxone)
• DUMBELS / cholinergic crisis, pin-point pupils, salivation → Organophosphate (atropine + oximes)
• Cherry-red skin + throbbing headache → Carbon monoxide (hyperbaric O₂)
• Bitter almond smell + red asphyxia (no cyanosis) → Cyanide (cyanide kit)
• Tinnitus + hyperventilation + mixed acid-base → Aspirin/salicylate (sodium bicarbonate)
• Bradycardia + AV block + hyperkalaemia → Digoxin toxicity (Digibind / digoxin immune Fab)
• Multiple radio-opaque foreign bodies in GIT → Body packing (whole bowel irrigation)
• Anaesthetic hypopigmented macule, 1–2 lesions + thickened palpable nerves → Tuberculoid leprosy (lepromin positive)
• Leonine facies + madarosis + numerous lesions, normal sensation → Lepromatous leprosy (lepromin negative)
• Subcutaneous nodules + pruritus + blindness; skin snips → Onchocerciasis / river blindness (ivermectin)
• Calabar swellings + worm crossing subconjunctiva → Loiasis (DEC; diurnal periodicity)
• Cherry-red spot at fovea + sudden painless vision loss + RAPD → CRAO ("stroke of the eye")
• "Blood and thunder" fundus (extensive haemorrhages) → CRVO
• Cotton wool spots + venous beading + IRMA → severe NPDR; neovascularisation on disc → proliferative DR (PRP)
• Macular drusen (early) / CNVM + metamorphopsia on Amsler grid → dry / wet AMD (anti-VEGF for wet)

Poisoning / toxidrome → antidote (as the index gives it)

Empiric coma cocktail (undifferentiated poisoning) = Dextrose · Naloxone · Thiamine (± Oxygen).

Criteria / scores / classifications at a glance

• OCD (ICD-11 / DSM-5): obsessions and/or compulsions; threshold >1 hour/day OR significant distress/impairment.
• Acute Stress Disorder (DSM-5): 5 symptom categories (intrusion + negative mood + dissociation + avoidance + arousal); duration 3 days–1 month after trauma.
• PTSD: duration >1 month; 4 core clusters — intrusion + persistent avoidance + negative alterations in cognition/mood + alterations in arousal/reactivity.
• ICD alcohol dependence: ≥3 of 6 features over past year (compulsion, difficulty controlling, withdrawal, tolerance, neglect of interests, persisting despite harm).
• Depression (ICD-10): ≥2 weeks, ≥2 of 3 core symptoms + additional (mild ≈4, moderate 5–6, severe ≥7 total).
• GAD: excessive worry most days ≥6 months. Panic disorder: recurrent unexpected attacks (peak ~10 min) + ≥1 month anticipatory worry.
• Mental capacity: 4 components (understand · retain · weigh & decide · communicate) + 5 principles (presumption of capacity, task/time-specific, support decisions, unwise ≠ incapacity, best-interests/least-restrictive).
• SADQ: <16 mild / 16–30 moderate / >30 severe dependence.
• AUDIT: 3 domains (hazardous · dependence · harmful use); AUDIT-C positive if ≥5.
• COWS: 7 parameters — resting pulse, sweating, restlessness, pupil size, bone/joint aches, runny nose/tearing, GI upset.
• Leprosy Ridley-Jopling: TT (stable, highest CMI, lowest load) → BT → BB → BL → LL (stable, lowest CMI, highest load).
• Leprosy WHO: Paucibacillary = 1–5 lesions (TT, BT); Multibacillary = >5 lesions (BB, BL, LL).
• Filariasis habitat: Lymphatic = W. bancrofti, B. malayi, B. timori · Cutaneous = Loa loa, O. volvulus, M. streptocerca · Body-cavity = M. perstans, M. ozzardi.
• Lymphoedema grading: I reversible on elevation · II not reversible, no skin changes · III non-pitting + skin thickening · IV nodular/warty excrescences (elephantiasis).
• Diabetic retinopathy staging: NPDR (background) → severe NPDR → proliferative DR → advanced diabetic eye disease.
• HTN retinopathy grading 0–4: grade 4 = grade 3 + disc swelling = malignant HTN emergency.
• Acid-base: Met acidosis ↓pH/↓HCO₃ (2° ↓pCO₂) · Met alkalosis ↑pH/↑HCO₃ (2° ↑pCO₂) · Resp acidosis ↓pH/↑pCO₂ (2° ↑HCO₃) · Resp alkalosis ↑pH/↓pCO₂ (2° ↓HCO₃).
• Anion gap: (Na⁺) − (Cl⁻ + HCO₃⁻); normal 8–12 mEq/L (no K), 12–16 (with K), 7 ± 4 mmol/L (alt deck value). Elevated AG = MUDPILES.
• BAC: UK drive limit 0.08 (80 mg/100 mL blood; 35 µg/100 mL breath); >0.50 → poisoning/death.
• Toxidromes (BP·P·RR·T·pupils): Anticholinergic ↑↑↑↑ pupils↑ (dry, flushed, retention, delirium) · Cholinergic ± (salivation/lacrimation/urination/bronchorrhoea/fasciculation) · Sedative-hypnotic all↓ · Opioid all↓ pupils↓ · Sympathomimetic ↑↑↑↑ pupils↑ (tremor/seizures) · EtOH withdrawal ↑↑↑↑ (tremor/seizures/hallucinations) · Opioid withdrawal (vomiting, rhinorrhoea, piloerection, diarrhoea, yawning).
• DUMBELS (muscarinic/OP): Diarrhoea, Urination, Miosis, Bradycardia/bronchospasm/bronchorrhoea, Emesis, Lacrimation, Salivation, Sweating.
• MATCH (nicotinic/OP): Muscle fasciculations, Adrenal medullary hyperactivity, Tachycardia/arrhythmias, Cramping skeletal muscle, Hypertension.
• CHIPES (radiopaque on AXR): Chloral hydrate, Heavy metal, Iron, Phenothiazine, Enteric-coated, Sustained-release.
• Disturbed behaviour hierarchy (5 stages): verbal de-escalation → time out → rapid tranquilisation → physical restraint → seclusion.
• Rapid tranquillisation: lorazepam 1–2 mg (max 4 mg/24h) ± haloperidol 5–10 mg (PO 30 mg/24h, IM 18 mg/24h); non-psychotic → lorazepam alone, psychotic → + antipsychotic; ensure flumazenil available; ECG for all who receive haloperidol.
• ABC model: Antecedents → Behaviour → Consequences; intervention = Prevention → Management → Harm reduction.
• MHA vs MCA: MHA = (possible) mental disorder, assessment/treatment of mental illness only; MCA = lack of capacity in dissenting patient, treatment in best interests.
• Observation levels: Constant (within hand reach) · L1 every 15 min · L2 every 30 min · L3 every hour.
• Egyptian Mental Health Act 2009: Art 11 voluntary hold max 72h (danger to self/others / unable to self-care; extension ≤1 week) · Art 12 minors/incapacitated (notify ≤2 business days) · Art 13 involuntary admission (psychiatrist + severe illness + refusing; notify ≤24h) · Art 14 non-psychiatrist admission max 48h (notify prosecutor ≤24h) · Art 16 stays >1 week (2 assessments; paperwork to Regional Council ≤7 days) · Art 17/18/21 transfers/escapes (urgent notify ≤24h) · Art 28 ongoing refusal (review ≤4 weeks; new assessment if forced Rx >3 months) · Art 29 emergency forced treatment max 72h · ECT (Art 28 & 30) = GA + muscle relaxer + written consent (max 2 emergency sessions) · Seclusion & restraints = last resort, 3 forms (physical, mechanical, chemical).

Discriminators that decide questions

1. Acute Stress Disorder vs PTSD — duration 3 days–1 month (ASD) vs >1 month (PTSD); symptoms beyond 1 month → PTSD.
2. Tuberculoid vs Lepromatous leprosy — TT: lepromin positive, highest CMI, lowest load, anaesthetic lesion, non-infectious, early nerve affection. LL: lepromin negative, lowest CMI, highest load, normal sensation in lesions, infectious, late nerve, leonine facies.
3. CRAO vs CRVO — CRAO: cherry-red spot at fovea, pale retina, attenuated vessels, embolus (ophthalmic emergency, first 15 min→1h). CRVO: "blood and thunder" extensive haemorrhages, engorged tortuous vessels, macular oedema.
4. Viper vs Cobra envenomation — Viper: hemotoxic + vasculotoxic (severe local pain, oedema, ecchymosis, gangrene, coagulopathy, myoglobinuria). Cobra: neurotoxic (minimal local pain/oedema, fasciculation → skeletal-muscle paralysis; consciousness + sensation spared).
5. Anticholinergic vs cholinergic toxidrome — Anticholinergic: dilated pupils, dry/flushed skin, urinary retention, delirium, hyperthermia, ↓bowel sounds. Cholinergic: salivation, lacrimation, urination, bronchorrhoea, fasciculation, paralysis.
6. Atropine vs oximes in organophosphate — atropine = muscarinic antagonist only (does NOT block nicotinic); oximes = reactivate AChE → correct all 3 (muscarinic + nicotinic + CNS), critical window first 24–48h before "aging".