A 26-year-old man presents with gum bleeding and petechiae over 5 days. CBC: Hb 9.0 g/dL, WBC 2,100/µL, platelets 22,000/µL. Fibrinogen is 90 mg/dL, D-dimer markedly elevated, PT and aPTT prolonged. Bone marrow shows abnormal promyelocytes with multiple Auer rods. What is the most appropriate immediate treatment?

• A Rituximab
• B Imatinib
• C Hydroxyurea
• D All-trans retinoic acid ✓

Explanation

The picture of acute promyelocytic leukaemia (FAB M3) with DIC is driven by the t(15;17) PML-RARA fusion. All-trans retinoic acid binds the PML-RARA receptor and triggers differentiation of the malignant promyelocytes, rapidly reversing the coagulopathy. Imatinib targets BCR-ABL in CML and Ph+ ALL, not PML-RARA. Hydroxyurea lowers counts in myeloproliferative neoplasms and does nothing for differentiation or DIC.

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.