Pulmonary embolism and thrombotic thrombocytopenic purpura in acute promyelocytic leukemia treated with all-trans retinoic acid.

We describe a patient with acute promyelocytic leukemia (APL) who developed pulmonary embolism (PE) and thrombotic thrombocytopenic purpura (TTP) during remission induction all-trans retinoic acid (ATRA) therapy. A 44-year-old man was diagnosed with APL and was treated with ATRA. On day 14, he developed PE, and on day 24, he developed TTP. Both PE and TTP occurred in association with leukocytosis due to ATRA administration. The PE responded to dexamethasone and TTP responded to plasma infusion. The PE and TTP remitted, and he achieved complete remission of APL. To our knowledge, there have been no reports of TTP occurring as a complication of ATRA therapy.