A rare case of male pelvic squamous cell carcinoma of unknown primary origin presenting as perineal abscess and urethral stenosis.

Carcinomas of unknown primary origin (CUP) represent a diagnostic and therapeutic challenge. Squamous cell CUP located in the male pelvis are very rare. We describe a case of a locally advanced squamous cell CUP occurring in the male pelvis presenting as perineal abscess and urethral stenosis and diagnosed by means of transperineal needle biopsy.