Embryonal rhabdomyosarcoma of the prostate.

We describe a case of embryonal rhabdomyosarcoma of the prostate in a 20-year-old man with a history of acute lymphatic leukemia at 6 years of age. He presented with gross hematuria and high fever. The level of prostate-specific antigen (PSA) was 27.9 ng/ml. Computed tomography revealed a suspected infectious cyst in the prostate. After antibiotic treatment was begun, the PSA level normalized. However, the patient later suffered bladder tamponade. A biopsy of the prostate revealed embryonal rhabdomyosarcoma. Chemotherapy with vincristine, actinomycin D, cyclophosphamide, and ifosfamide was begun according to the treatment protocol of the Japan Rhabdomyosarcoma Study Group. The tumor shrank, and partial remission was obtained after 1 course of chemotherapy. During treatment for acute lymphatic leukemia at the age of 6 years, the patient had been exposed to a cumulative radiation dose of 10 Gy across his entire body. It has been reported that 88% of postradiation sarcomas are KIT-positive, and we suspect that our patient suffered a postradiation sarcoma, because his tumor was KIT-positive. This is the first report of postradiation sarcoma manifesting as an embryonal rhabdomyosarcoma of the prostate.