Metastatic melanoma to the bladder

Abstract

Introduction. Metastatic tumor compromise of melanoma to the genitourinary tract is frequent, but metastasis to the bladder is rare, representing less than 2% of cases. However, autopsies performed on patients with melanoma have found metastases in the bladder in 18-37% of cases, making it the second incidence after gastric adenocarcinoma. The median survival is usually 6 to 7.5 months. The objective of this work is to present the case of a metastatic melanoma to the bladder, a rare and underdiagnosed condition because most of the time it is asymptomatic. Case Presentation. 62-year-old female patient, with a history of melanoma at the level of the first toe, with surgical and pharmacological management. The reason for consultation was hematuria. Cystoscopy revealed a single solid, erythematous lesion with necrosis and easy bleeding, and a transurethral resection (TUR) was indicated. The pathology found compromise for metastatic ulcerated melanoma. Second-line treatment (Pembrolizumab) was started and presented progression to the upper limbs and relapse at the bladder level. The patient died a year later. Discussion. Melanoma metastases to the genitourinary tract are common, but isolated bladder metastases are rare. Treatment is usually TUR of the lesion, cystectomy, chemotherapy, and radiation therapy. TUR is curative for lesions restricted to the epithelium, although radical cystectomy is usually the therapy of choice in patients with a localized tumor. Pembrolizumab has been shown to increase survival. The prognosis depends on the size and depth of the invasion. Conclusions. Metastatic bladder compromise is rare and underdiagnosed, it may be present in patients with melanoma, non-specific urinary irritative symptoms, and hematuria. It tends to have a poor prognosis, and requires surgical management associated with systemic management.