Carcinosarcoma of penis. Case report and review of the literature.

: AIMS OF THE STUDY: Carcinosarcomas (sarcomatoid carcinomas) are controversial, biphasic tumors composed of both carcinomatous and sarcomatous elements. They are uncommon and occur in numerous locations. At the time of this report only 3 cases of carcinosarcoma of penis have been reported in the literature. The aim of this article is to provide a discussion of these lesions, using informations gleaned from the pertinent literature as well as the personal experience of the authors. METHODS: The formalin-fixed paraffin-embedded tissue was stained with hematoxylin and eosin, reticulum, alcian blue and Mallory's trichrome stains. Section from selected paraffin-embedded blocks, were stained with antibodies to citokeratins, EMA, vimentin, desmin, and a actin. RESULTS: In our case the carcinomatous elements were admixed with areas of "divergent differentiation": spindle-cell and giant-cell sarcomatoid component with bone and cartilage differentiation were noted. In situ carcinoma was also detected. Immunohistochemistry showed reactivity for keratin and epithelial membrane antigen (EMA). In most of pleomorphic spindle elements. Immunoreactivity for vimentin, desmin and actin were focally found. CONCLUSIONS: The carcinosarcomas may demonstrate "divergent" differentiation into bone, cartilage or myogenous tissue, so it is possible that the cell of origin could be heterogeneous. In our case myogenous differentiation was focally found. Although the clinical data, available from the only three cases of the literature, demonstrate that the behaviour of this tumors was not different from those of squamous cell carcinoma, the authors recommended a constant careful follow-up of the patients.