A 38-year-old woman with acute promyelocytic leukemia (APL) presents to the emergency department with spontaneous bleeding from gums and petechiae over the trunk. She was diagnosed 3 days ago and started on ATRA and arsenic trioxide. Blood pressure is 95/58 mmHg, heart rate 118/min. Laboratory findings: Hb 7.2 g/dL, platelets 18,000/μL, PT 18 sec (control 12), aPTT 52 sec (control 36), fibrinogen 95 mg/dL (normal 200–400), D-dimer markedly elevated. Peripheral blood shows abnormal promyelocytes with Auer rods. What is the most likely diagnosis?