Evidence for cyclophosphamide-induced transitional cell carcinoma in a renal transplant patient.

Cyclophosphamide treatment has been associated with bladder cancer in a number of case reports but no causal relationship has been proved since nearly all of these patients were treated with the drug for malignant disease. We describe a patient who received cyclophosphamide after cadaveric renal transplantation to prevent rejection. Transitional cell carcinoma developed in the native bladder and in the donor transplanted ureter (20-year-old donor) 13 years later despite no identifiable risk factors. This case strengthens the argument that cyclophosphamide has a carcinogenic potential on the urinary tract epithelium.