Primary melanoma of the bladder: case report and review of the literature

Abstract Background: Primary melanoma of the urinary bladder is extremely rare and has been sporadically reported in case reports. Its incidence, diagnosis, treatment, and outcomes are still unclear. Case presentation: We report a case of 67 years-old female patient who presented with hematuria and was diagnosed with primary melanoma of the urinary bladder by transurethral resection of bladder tumor. Fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) revealed no lymph node nor distant metastasis. After multidisciplinary discussion, the patient received laparoscopic radical resection of bladder tumor. There was no tumor recurrence or distant metastasis after 10 months of follow-up. Conclusion: Primary melanoma of the urinary bladder is easily confused with urothelium carcinoma in morphology. The immunohistochemical is crucial in diagnosis. Because of lack of in-depth understanding of primary melanoma of bladder, "Gold standard" treatment has not been set. We would like to provide some rare information about primary melanoma of the urinary bladder and discuss the best strategy for the treatment of rare disease.