Rhabdomyosarcoma of prostate in adult. Long-term survival and problem of histologic diagnosis.

Only 1 case of primary rhabdomyosarcoma of the prostate in an adult with a five-year survival has been described previously. Reported here is a case of a recurrent lesion initially diagnosed as a fibroepithelial polyp and then later recognized to be rhabdomyosarcoma. Radical surgery was not performed, yet the patient survived seven years before dying of generalized metastatic rhabdomyosarcoma. This course represents a unique pathobiology for primary rhabdomyosarcoma of the prostate. It also demonstrates a histologic continuum between fibroepithelial polyp and rhabdomyosarcoma in which the pathognomonic features of the sarcoma were not recognized until two years after the initial biopsy. This argues for an increased index of suspicion for sarcoma of the prostate in a young person with a prostatic nodule even in the face of a benign-looking initial biopsy.