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A candidate is asked to manage a classic presentation of Acute Leukaemia (AML & ALL, including APL) in an exam setting. Use precise definitions, scores, doses, and decision thresholds.
Core knowledge (model answer backbone)
Acute leukaemia is a clonal malignancy of haematopoietic blasts arrested at an early stage of differentiation, defined by marrow blasts at least 20 percent (or a defining genetic lesion), that crowds out normal haematopoiesis producing anaemia, infection and bleeding. It divides into acute myeloid leukaemia (AML) — the commonest acute leukaemia of adults, driven by recurrent mutations (FLT3, NPM1, CEBPA) and classified by the WHO 2022 / ELN 2022 genetic risk groups — and acute lymphoblastic leukaemia (ALL) — the commonest childhood cancer, divided into B-ALL and T-ALL and transformed in adults by the Philadelphia chromosome t(9;22) BCR-ABL1. Acute promyelocytic leukaemia (APL, FAB M3) is a separate haematological emergency: t(15;17) PML-RARA, a differentiation block at the promyelocyte stage and life-threatening DIC, treated with differentiation therapy — ATRA plus arsenic trioxide — which has made APL the most curable acute leukaemia. AML induction is '7+3' cytarabine plus daunorubicin; unfit AML receives azacitidine plus venetoclax; ALL receives multi-agent induction (vincristine, steroids, asparaginase, anthracycline) plus CNS-directed intrathecal therapy, with TKIs (imatinib/da
Red flags
- Bleeding with low fibrinogen, prolonged PT/aPTT and high D-dimer —suspected APL/DIC: start ATRA immediately on suspicion, before genetic confirmation; do not wait
- Acute leukaemia with WBC over 100 times 10^9/L plus confusion, visual disturbance or dyspnoea — symptomatic leucostasis; leucopheresis, hydroxycarbamide, urgent cytoreduction
- High-burden, high-WBC or proliferative acute leukaemia starting therapy — tumour lysis syndrome; aggressive IV hydration plus rasburicase, monitor K+/phosphate/Ca2+/urate/creatinine q4-6h
- Neutropenic patient (post-chemo, ANC under 0.5) with fever over 38.3C — febrile neutropenia; empirical broad-spectrum anti-pseudomonal beta-lactam within one hour
High-yield structure examiners expect
Cover: Overview & Definition, Classification, Epidemiology & Risk Factors, Pathophysiology, Clinical Presentation, Differential Diagnosis.
Key doses / thresholds (from topic teaching)
- plus WHO 2022 genetic groups and ELN 2022 risk) versus
- potassium over 6.0 mmol/L or 25 percent rise**, **phosphate ove
- calcium under 1.75 mmol/L or 25 percent fall**
- Piperacillin-tazobactam 4.5 g IV every 6 to 8 hours** (first-line in
- Meropenem 1 g IV every 8 hours** (if prior resistant
- Ceftazidime 2 g IV every 8 hours** (alternative)
Questions
a) Define the condition and give the most important classification or severity framework used in exams. (3 marks)
- Clear one-line definition matching standard teaching.
- Named classification / stages / types with discriminating features.
- One sentence on why classification changes management.
b) Outline pathophysiology in a mechanism chain that explains the main clinical features. (3 marks)
- Initiating insult → intermediate pathway → end-organ effect.
- Link at least two symptoms/signs to mechanism.
- Mention one complication pathway (e.g. shock, perforation, herniation, arrhythmia).
c) List discriminating clinical features and bedside assessment. (3 marks)
- Classic presentation plus one atypical group (elderly, pregnancy, child, immunocompromised).
- Named signs/manoeuvres if relevant.
- What must never be missed on exam/bedside (pregnancy test, airway, glucose, etc.).
d) Investigations with thresholds and one named score if applicable. (3 marks)
- First-line tests and what positive findings mean.
- Gold-standard or definitive investigation when needed.
- Score components reproduced exactly if a named score is standard for this topic.
e) Immediate resuscitation and definitive management with doses where standard. (3 marks)
- ABC / time-critical steps first.
- First-line drug(s) with agent + dose + route (or procedure steps).
- Escalation triggers (theatre, ICU, thrombolysis window, antidote, etc.).
- Disposition and safety-netting.
Marking tips
Full marks require specificity (numbers, names, doses) not generic "give antibiotics/fluids." Regional practice (ICMR / NICE / AHA) may be cited as alternative where relevant.