Primary malignant melanoma of the bladder

Abstract

Primary malignant melanomma of bladder is extremely rare: 18 cases are reported to date. An 82 year-old man underwent trans-urethral resection of bladder for a bleeding tumor of the posterior wall. Histological diagnosis was melanoma of the bladder. There was no history of previous or regressed cutaneous malignant melanoma. Margins of the bladder lesion contained atypical melanocytes similar to those commonly seen in the periphery of primary mucous membrane lesions. Clinical studies and radiological examinations were negative for other primary site of melanoma. The patient had a bladder recurrence that was consistent with primary tumor and died of widespread disease 9 months after diagnosis.

Malignant melanoma of the bladder: A case report

“…Most previously reported cases of primary bladder melanomas showed a strong pigmentation. 1,[2][3][4][5][6][7][8][9] In our case, the pigment was very scant, similar to what had been found in the case of Ahlen and colleagues. 11 In such cases, immunohistochemical study is required.…”

“…Most cases presented hematuria and/or dysuria as initial symptoms. 1 This was the case for our patient.…”

“…4 Despite the variety of therapies available for primary melanomas of the bladder, the prognosis is still poor. 1,5 We report a case of hypomelanotic malignant melanoma of the bladder, which mimics high-grade urothelial carcinoma.…”

“…1,2 While the urethra and penis are the most common sites of origin of primary malignant melanoma in the genitourinary tract, the prostate, renal pelvis, ureter, and bladder are less common. 3 Rather than being a primary lesion, malignant melanomas of the bladder are more commonly metastatic lesions, which originate from a distant primary site.…”

Malignant Melanoma in Genito-Urinary Tract

“…Renal (45 %), and vesical (18 %) metastases had been found in patients deceased because of melanoma. 44 Therefore, discrimination between primary and metastatic melanomas of the bladder is crucial. Stein 45 and Ainsworth 46 established some diagnostic criteria for primary bladder tumors: (1) absence of any previous skin lesion (2) or cutaneous malignant melanoma (3) or primary visceral malignant melanoma (4) recurrence pattern showing consistency with the primary tumor diagnosis (5) atypical melanocytes at the tumor margin on microscopic examination.…”