Primary genitourinary melanoma presenting as voiding dysfunction.

A case of primary malignant melanoma of the urethra in a 67-year-old female is presented. Cystourethroscopy performed during a workup for pelvic organ prolapse revealed a bladder and urethral mass. Initial histologic examination was interpreted as undifferentiated sarcoma; however, after immunohistochemical staining by two separate institutions, malignant melanoma was diagnosed. Being rare, urethral melanoma is often misdiagnosed, and treatment can be delayed. Given its poor prognosis, early diagnosis is essential, and clinicians need to include it in their differential when working up a patient with genitourinary complaint.