Primary carcinoma of fossa navicularis.

A case of primary carcinoma of the fossa navicularis of the male urethra is discussed. The lesion presented as an ulcerative process that circumferentially involved the external urinary meatus in a sixty-three-year-old man. Initially, the lesion was confused with a superficial carcinoma of the penis, since results of urethroscopic examination were normal. Following midshaft penectomy, despite normal gross appearance of the distal urethra, histologic examination indicated poorly differentiated epidermoid carcinoma along the mucosa of the distal urethra up to the line of surgical resection. Subsequent total penectomy showed only a small area of residual tumor at the line of previous resection. Lymphadenectomy was not performed. The patient remains alive without evidence of residual disease five years later.