Carcinosarcoma of the prostate in a patient with previous prostatic adenocarcinoma, status post brachytherapy

Carcinosarcoma of the prostate is an exceedingly rare form of prostate cancer. Prognosis is poor, and the observed biological behavior of these tumors is to be very aggressive irrespective of histologic variants. Some authors speculate that the increasing use of external beam radiation therapy and brachytherapy in the treatment of prostatic adenocarcinomas may raise the incidence of carcinosarcoma. We present the case of a 71 year-old Caucasian male with a history of prostatic adenocarcinoma treated with brachytherapy seven years ago. The patient developed progressive genitourinary symptoms leading to impotence and severe urinary obstruction. This was followed by cystoprostatectomy and incidental pathology diagnosis of carcinosarcoma of the prostate. Fluorescent in situ hybridization study for amplification of the c-Myc gene, frequently seen in radiation-induced sarcomas, was negative. Carcinosarcomas of the prostate show general similarities of clinicopathologic features regardless of histologic variants or etiology. Our case, as well as the accompanying review of the literature, highlights the complexity of diagnosis of prostatic carcinosarcoma, as well as its continued poor prognosis. Due to the limited number of available cases, it is not possible to conclude at this time whether or not there is a causative association of this tumor with prior radiation therapy of the prostate.