Primary melanoma of the bladder: Case report and review of the literature.

Skin melanoma represents one of the most common and lethal solid tumor. It usually develops on the skin but it can occur in any tissues with melanine- containing-cells (extracutaneous malignant melanoma). Only 4-5% of malignant melanomas originate in extracutaneous tissues, and they have an extremely lethal behavior (1). These non-skin malignant melanomas are rare but extremely aggressive. Primary melanoma of the genitourinary tract accounts for less than 0.2% of all melanomas. To date only 28 cases of primary bladder melanoma (PMM) are described. We report a rare case of PMM of the bladder in a 72 years old man treated with radical cystectomy and immunotherapy with Nivolumab.