Primary malignant melanotic melanoma and hypomelanotic melanoma of the female urethra: case series and a review of the literature in China.

The incidence of primary malignant melanoma (MM) of female urethra is extremely low, leading to paucity of recommendations on management. The objectives of our study were to gain more insight into the clinical features, diagnosis, treatment, and prognosis of this rare type of tumor. We carried out a retrospective analysis of all four cases who underwent an operation in our hospital since 1980. Moreover, other 32 cases of MM that have been reported in Chinese papers were also included for further review. The age of the patients ranged from 38 to 81 years. A mass in the urethral meatus and hematuria are common presentations. The final diagnosis depends on histopathological examination. After surgery alone or combined with chemotherapy/radiotherapy/immunotherapy, all cases were followed for 1-151 months, whereas only one lived for more than 4 years after receiving the diagnosis. A timely and accurate diagnosis of MM is critical, especially for hypomelanotic and amelanotic cases. Immunohistochemical staining and electron microscopy are necessary for a precise diagnosis in some cases. Extensive resection, early chemotherapy, and immunotherapy may help to improve survival.