Primary enteric-type mucinous adenocarcinoma of the urethra in a patient with ulcerative colitis.

Primary carcinoma of the male urethra accounts for less than 1% of malignancies in men. Mucinous adenocarcinoma of the urethra is extremely rare, and its biologic behavior is poorly understood. We present herein a rare case of mucinous urethral adenocarcinoma in a male patient with longstanding ulcerative colitis and multiple sclerosis. The patient presented with a voluminous pelvic mass; core biopsy of the lesion demonstrated a mucus-producing adenocarcinoma. Given the patient's history of subtotal colectomy, preoperative diagnosis was oriented towards a rectal stump adenocarcinoma. The patient underwent a pelvic exenteration: surprisingly, histology marked the prostatic urethra as the primary lesion site.