PE26.8 | Acute Lymphoblastic Leukemia — Summary & Reflection

KEY TAKEAWAYS

Acute lymphoblastic leukaemia — key points:

• ALL is the most common childhood malignancy (~30% of all childhood cancers, ~80% of childhood leukaemias); peak age 2–5 years.
• Presentation: marrow failure triad (anaemia + thrombocytopenia + neutropenia) + hepatosplenomegaly + lymphadenopathy + bone pain. T-ALL may cause mediastinal mass and SVC syndrome.
• CBC + peripheral smear: blasts on smear in a child with the above picture = haematological emergency.
• Diagnosis: bone marrow aspirate with ≥25% blasts + immunophenotyping (B-ALL: CD10/CD19+; T-ALL: CD3/CD7+) + cytogenetics.
• Critical distinction from ITP: hepatosplenomegaly, lymphadenopathy, anaemia, and blasts on smear are absent in ITP. Never give steroids for thrombocytopenia without excluding ALL.
• Risk stratification: standard risk (age 1–9 yr, WBC <50,000/µL, B-ALL, good MRD response); high risk (age <1 or ≥10 yr, WBC ≥50,000/µL, T-ALL, BCR-ABL1, slow MRD response).
• Treatment: induction (VCR + pred + L-Asp ± anthracycline) → consolidation (HD-MTX + IT-MTX for CNS prophylaxis) → maintenance (daily 6-MP + weekly oral MTX) × 2–3 years.
• Tumour lysis syndrome: hydrate aggressively + allopurinol BEFORE chemotherapy; monitor electrolytes/uric acid frequently.
• 5-year overall survival with modern protocols ≥85–90% in standard-risk patients.

REFLECT

Apply Kolb's experiential learning cycle to this module:

Concrete Experience: Think back to the opening case — the 4-year-old with 94,000 WBC, blasts on smear, and organomegaly. What was your initial clinical reasoning, and how did it change as each investigation result returned?

Reflective Observation: Consider a scenario where a child with ALL presents initially with only thrombocytopenia and is treated for ITP. What clinical features, if carefully assessed from the beginning, would have raised the suspicion that this was not ITP?

Abstract Conceptualisation: The three phases of ALL treatment (induction, consolidation, maintenance) serve three distinct biological goals. Can you articulate — in one sentence each — the precise goal of each phase and why removing any one phase from the protocol would increase relapse risk?

Active Experimentation: In your next clinical posting, practise systematically examining the spleen and liver in every child presenting with pallor, bruising, or unexplained fever. Document your findings and compare the clinical picture with subsequent CBC results.