Synchronous melanosis of upper and lower urinary tract.

Urothelial melanosis is an exceptionally rare diagnosis, with less than 25 cases being reported in the literature. Melanosis of the urothelium is characterized by abnormal melanin deposition within tissues, producing a black, velvety appearance to the urothelial mucosa. We present a 67-year-old male undergoing cystoscopy during a routine percutaneous nephrolithotomy (PCNL), who was found to have diffuse bladder melanosis extending up the ureter and into the renal pelvis. To our knowledge, this is the first reported case of synchronous melanosis of upper and lower urinary tract.