Primary malignant melanoma of the urinary bladder.

Primary malignant melanoma is an unusual neoplasm in the urinary bladder that is infrequently found in association with melanosis. We report a case of bladder-invasive malignant melanoma with melanosis in which the melanosis exhibited melanocytic atypia extending through to melanoma in situ and was diagnosed by immunohistochemical techniques using a monoclonal antibody, HMB-45. To our knowledge, such findings have not been reported previously.