Primary malignant melanoma of the urethra.

Primary malignant melanoma of the urethra is an aggressive neoplasm associated with a poor prognosis. The outcome is dependent on early diagnosis and surgical intervention. However, the diagnosis is often delayed as a result of difficulties related to differentiating this lesion from other disorders. Such difficulties result from the variety of clinical and pathologic presentations that are common to melanoma. We report a case of primary malignant melanoma of the urethra with subsequent retrograde seeding of the bladder initially diagnosed and managed as invasive urothelial carcinoma.