An 8-year-old boy presents with a 2-week history of fever, fatigue, bone pain, and easy bruising. Examination reveals pallor, petechiae, and non-tender lymphadenopathy with splenomegaly. CBC shows Hb 6.5 g/dL, WBC 60,000/mm3, platelets 18,000/mm3. Peripheral smear shows numerous blasts. What is the most likely diagnosis, and which immunophenotype carries the best prognosis?

• A AML-M3 (acute promyelocytic leukemia); best prognosis with ATRA
• B Acute lymphoblastic leukemia (ALL); common B-precursor (CD10+/CALLA+) type carries best prognosis ✓
• C Chronic myeloid leukemia (CML); Philadelphia chromosome positive
• D Burkitt lymphoma; L3 morphology carries best prognosis

Explanation

ALL is the most common malignancy in children (peak age 2-5 years, but this boy at 8 years is within the common range). Fever, bone pain, pancytopenia with blasts, lymphadenopathy, and splenomegaly are classic features. The most common subtype is pre-B cell ALL (CD10+/CALLA positive, also called common ALL), which has the best prognosis with modern chemotherapy, achieving over 85-90% long-term event-free survival. This is in contrast to T-cell ALL or infant ALL (<1 year), which carry worse prognoses.

Reference: Ghai Essential Pediatrics, 10th ed.

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Written and medically reviewed by the StethoPrep medical team.