Pancreatitis in Acute Promyelocytic Leukemia: Drug-induced or Differentiation Syndrome?

Acute promyelocytic leukemia (APL) constitutes about 15% of all acute myeloid leukemia patients and can now be treated even without any chemotherapy, with all-trans-retinoic acid (ATRA) and arsenic trioxide (ATO). Acute pancreatitis (AP) is a rare adverse event in APL, which is primarily reported to be secondary to hypertriglyceridemia. Here, we have reported AP developed in a patient of APL, during induction with ATRA and ATO, but it was not associated with hypertriglyceridemia. Rather, it was associated with respiratory distress and weight gain, coincidental leukocytosis, bilateral pleural effusion, and edematous pancreatitis without any necrosis. Hence, AP in this case is diagnosed to be a manifestation of differentiation syndrome, and it responded to steroid.