Acute promyelocytic leukemia after renal transplant and filgrastim treatment for neutropenia.

Prolonged immunosuppression in solid organ transplant recipients has been considered a risk for developing opportunistic infections and malignancies. Acute leukemia is a rare complication. We report a case of acute promyelocytic leukemia (APL) (FAB M3) after cadaveric renal transplant for focal segmental glomerulosclerosis in a 24-year-old woman. Her immunosuppressive therapy included tacrolimus, mycophenolate mofetil, and prednisone. Approximately 2 years after transplant, she became pancytopenic, prompting administration of filgrastim. A few doses caused a markedly increased blast count, resulting in a diagnosis of APL. She was successfully treated with all-trans-retinoic acid and arsenic trioxide. Myeloproliferative neoplasms after organ transplant or due to filgrastim are rare.