A 32-year-old woman presents with gum bleeding, petechiae, and fever. CBC: WBC 34,000/uL, Hb 7.8 g/dL, platelets 22,000/uL. PT and aPTT are prolonged, fibrinogen is 90 mg/dL, and D-dimer is markedly elevated. Peripheral smear shows abnormal promyelocytes with bilobed nuclei and dense granules. Which cytogenetic abnormality defines this condition?
- A t(8;21)(q22;q22)
- B t(15;17)(q24;q21) ✓
- C inv(16)(p13q22)
- D t(9;22)(q34;q11)
Correct answer: B. t(15;17)(q24;q21)
Explanation
The combination of DIC at presentation and abnormal promyelocytes is acute promyelocytic leukaemia (AML-M3), defined by t(15;17) producing the PML-RARA fusion transcript. ATRA targets this receptor and rapidly corrects the coagulopathy. inv(16) and t(8;21) are core binding factor leukaemias with a favourable prognosis but do not cause early fatal DIC, which is the discriminating feature here.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.