[Mucosal melanoma primary and metastatic cases with urogenital localization in our department]

Both primary and metastatic cases of mucosal melanoma in urogenital localization are rare tumors. Only 4-5% of all primary melanomas do not arise from the skin. Extracutaneous melanomas have a complex clinical presentation, but these aggressive tumors have a poor prognosis.

In our department, we found 7 patients with malignant melanoma of the genitourinary tract in the past few years. The 7 cases were: primary amelanotic melanoma of the female urethra, a primary melanoma of the bladder, two primary melanomas of the penis, a metastatic melanoma of the urethra and another to the testis and a metastatic melanoma of the bladder with melanuria. We retrospectively analyzed the available data to describe the presentation, management, and clinical outcome of the patients.

In the three inoperative cases, palliative, urologic surgical procedures and systemic antitumor therapy were performed. Two of the four primary urogenital tumors were localized to the penis. In one case, local recurrence developed after surgical treatment, but with a radical, repeated surgery, the patient has been asymptomatic for a year and a half. In the other, neglected case, the penis melanoma spread through the urethra and the inguinal lymph nodes two years after radical surgery and inguinal block dissection. In the female primary urethral melanoma case, the first histological study reported a primary mesenchymal tumor, and the recurrent tumor that occurred one and a half years later showed melanoma diagnosis. Radical surgery performed because of urethral involvement resulted in a 5-year asymptomatic state, followed by local recurrence and distant metastasis. In the fourth case of a primary bladder melanoma, the rapid progression of the disease and the BRAF positivity of the tumor suggested that not the firstly diagnosed bladder melanoma was the primary tumor.

The occurrence of urinary tract melanoma is very rare and its discovery happens often in a disseminated state, so the expected prognosis of the cases is also poor. The most important factors for increasing therapeutic efficacy are early diagnosis and radical surgical intervention. Tumors appearing in different localizations require different urological surgical approaches. The literature recommendations for treatment are not uniform. Their prognosis is worse compared to the cutaneous melanoma, which may be due to clinical and pathological diagnostic difficulties. The latest targeted and immunotherapeutic agents can significantly improve the survival of metastatic patients. Orv Hetil. 2019; 160(10): 378-385.