Acute myelocytic leukemia after the use of cyclophosphamide in the treatment of polyarteritis nodosa.

The use of cyclophosphamide has been associated with the delayed appearance of neoplasms. We report a woman who developed myelodysplastic syndrome leading to acute myelocytic leukemia, 4 years after receiving 13 g of cyclophosphamide over 6 months for severe polyarteritis nodosa. Cytogenetic abnormalities typical of damage induced by alkylating agents, including partial deletions of chromosomes 5 and 7, were present. This case represents the first reported occurrence of cyclophosphamide associated malignancy in polyarteritis nodosa.