[Metastatic malignant melanoma of the urinary bladder presenting with hematuria: a case report].

A 65-year-old man complained of macroscopic hematuria and urinary obstruction. A blood clot in the bladder eliminated transurethrally demonstrated a solitary tumor at the dome of the bladder. Transurethral resection of the bladder tumor (TUR-Bt) was performed, and histological diagnosis was malignant melanoma. Physical examination revealed a black-pigmented site on the lateral border of the right foot sole, which was dermatologically diagnosed as malignant melanoma. The vesical site was diagnosed as a metastatic melanoma of the bladder. Metastatic neoplasms of the bladder are rare, ranging from 0.1 to 6.2 percent of all bladder tumors. To our knowledge, approximately forty percent of metastatic neoplasms of the bladder originate from melanoma. Therefore, an atypical nodular lesion encountered during cystoscopy may be metastasis of malignant melanoma and dermatic lesions should be investigated.