Mixed papillary-sarcomatoid carcinoma of the penis: report of an aggressive subtype.

Several different histological subtypes of penile carcinoma had been described in the last decades, many with different biological behavior and prognosis. The association of two histological subtypes (mixed tumors) can be observed in one third of the cases. The most common association is of warty and basaloid tumors, two HPV-related carcinomas. Here, we described a mixed papillary-sarcomatoid carcinoma, never reported before. Although it is a clinical aspect of a low-grade verruciform tumor, its prognosis showed it to be very aggressive due to the sarcomatoid component hidden above the papillary component. The two components showed opposite cadherin/vimentin expression pointed to epithelial-mesenchymal transition between them.