High-grade transitional cell carcinoma and melanosis of urinary bladder: case report and review of the literature.

Melanosis of the urinary bladder is a rare entity. It is generally regarded as a benign condition, but it is sometimes associated with primary malignant melanoma of the urinary bladder. It has never been reported to be connected with transitional cell carcinoma. We present a case of a woman with melanosis of the bladder who a year later developed high grade transitional cell bladder carcinoma.