Primary Melanoma of the Bladder

Exploring the landscape of urinary tract melanomas: A review for pathologists and clinicians

Melanomas originating within the urinary tract represent a rare and clinically challenging subset of malignancies. Despite extensive research on cutaneous melanomas, urinary tract melanomas remain relatively unexplored, presenting diagnostic dilemmas and limited treatment consensus. In this comprehensive review, we synthesize current knowledge on the epidemiology, risk factors, clinical presentation, histopathological characteristics, and treatment strategies specific to this disease. Enhancing clinical awareness, refining diagnostic approaches, and exploring novel therapeutic interventions hold promise for improving outcomes in this challenging malignancy subset.

Genitourinary melanoma: An overview for the clinician

Genitourinary (GU) melanoma is a rare presentation of melanoma accounting for approximately 0.5% of all melanomas. GU melanomas include primary melanomas of the vulva, vagina, uterine cervix, ovary, penis, scrotum, urethra, bladder, ureter, and kidney. These melanomas are often diagnosed in advanced stages and stigma is thought to contribute to delays in presentation. As the likely diagnosing provider, it is imperative that dermatologists, urologists, and gynecologists are aware of these uncommon sites of presentation. While there have been major advances in the treatment of melanomas as a whole in the last 10 years, their applications to GU melanomas have often been overlooked. GU melanomas have not been included in many of the major phase III clinical trials which brought contemporary advanced treatments to market and the prognoses for GU melanomas remain poor. Due to the rarity of GU melanomas, much of the literature provides generalized recommendations across multiple different organs affected by GU melanomas or omits certain topics, making it difficult to appreciate the fundamentals of the individual presentations. This review aimed to provide background information on the pathogenesis and epidemiology of the different sites of GU melanomas and categorize data specific to the presentation, staging, treatment, and prognosis of each type of GU melanoma to guide the clinician. It was also meant to encourage a multidisciplinary approach to the management of these patients as it spans the expertise of surgical oncologists, medical oncologists, radiation oncologist, dermatologists, urologists, and gynecologists.

Urological Melanoma: A Comprehensive Review of a Rare Subclass of Mucosal Melanoma with Emphasis on Differential Diagnosis and Therapeutic Approaches

Melanoma is reported as the 19th most common cancer worldwide, with estimated age-standardized incidence rates of 2.8-3.1 per 100,000. Although the origin is most frequently cutaneous, mucosal melanoma has been described several times in literature, and despite its rarity (only 1% of all melanomas), increasing attention is being paid to this disease form. Within this subgroup, melanomas of the uropoetic apparatus are a rarity among rarities. Indeed, less than 50 cases of primary melanoma originating from the urinary bladder have been described, and even less originating from the kidney, renal pelvis and urethra. In this work, we present a detailed review of the literature related to this subclass of mucosal melanoma, delve into the biological landscape of this neoplasm and discuss current approaches, future perspectives and potential therapeutic approaches.

The color of urine: then and now-a comprehensive review of the literature with emphasis on intracytoplasmic pigments encountered in urinary cytology

The color of urine, once considered by uroscopists to give the most important clues to the diagnosis, still can provide some diagnostic clues in modern medicine. Pigmented cells are an uncommon and surprising find in urine cytology and can at the same time provide important diagnostic clues or represent a dangerous pitfall. We present a review of the significance of pigmented cells in urine cytology. The presence of intracellular pigment granules; their color, size, shape, and variation in size and shape; as well as their staining reactions with special stains can provide useful diagnostic insight, especially when interpreted in the cytologic context (type of pigmented cell and its degree of atypicality) and patient's clinical context. The main differential diagnosis of cytoplasmic pigmented granules includes hemosiderin, lipofuscin, and melanin, each having a different pathogenesis and significance. The goal of this paper is to describe the morphological, histochemical, and ultrastructural characteristics of the pigments seen in urinary cytology, and to review the benign and malignant conditions associated with them.

Primary malignant melanoma of the urinary bladder: clinical, morphological, and molecular analysis of five cases

The aim of our study was to evaluate the clinical and morphological features of primary malignant melanomas of the urinary bladder. We obtained information on five such cases from three different institutions. These were three men and two women between 52 and 76 years of age. Three tumors presented with hematuria, one with dysuria, and one was discovered incidentally on imaging studies. All were invasive to muscularis propria on transuretral resections performed for diagnosis. Neoplastic cells showed variable patterns (large cell epithelioid, small cell diffuse, storiform, or mixed) in different tumors. Pigmentation was prominent in all except one case. Each case was labeled diffusely for S-100, HMB-45, and Melan-A. Pan-cytokeratin showed a perinuclear dot-like reaction in two tumors. Three cases showed the BRAF mutation in molecular studies. Two patients were already metastatic at the time of diagnosis. Two patients died, one is alive with disease after 15 months, and two patients are disease free at 1 and 5 years of surveillance.

Melanoma of the urinary bladder: a review of the literature

Background. Melanomas of the urinary bladder and urethra are rare. Aims. To review the literature on the disease. Methods. Various Internet databases were used to identify reported cases of the disease. Results. Less than 30 cases of primary melanoma of the urinary bladder and urethra have been reported in the literature and they have been associated with melanosis and commonly with metastases. The lesions may be primary or metastatic with no gender preference. The diagnostic features include pigmented raised lesions which histologically exhibit spindled or epitheliod cells, necrosis, mitotic figures, and atypical melanocytes. Immunohistochemically they stain positively with S100; HMB45; and other melanocyte markers, but negatively with Keratin and Vimentin. The treatment involves excision and possibly IL-2. The prognostic factors include size and depth of invasion as well as metastatic lesions. Conclusions. Less than 30 cases (about 24 cases) of the disease have been reported. There are also reports of metastatic melanomas of the urinary bladder emanating from primary melanomas originating elsewhere. Diagnosis of the primary disease is based upon the histological appearance of the lesion, positive staining with S100 and HMB45, and evidence of absence of melanoma elsewhere. Primary melanoma of the bladder is usually a fatal lesion.

Primary Malignant Melanoma of the Genitourinary Tract with Upper and Lower Tracts Involvement

A 91-year-old female presented with lower extremity swelling and shortness of breath. Laboratory analysis revealed elevations in blood urea nitrogen and creatinine along with microscopic hematuria on urinalysis. Computed tomography imaging showed moderate right hydronephrosis with dilatation of the proximal ureter with a soft tissue density at a transition point. Endoscopic evaluation revealed multiple raised, fleshy, and hemorrhagic masses throughout the bladder which are present in both ureters. Biopsy of these lesions revealed malignant melanoma invading the lamina propria. No dermatologic lesions were identified suggesting a primary malignant melanoma of the genitourinary system.

A rare case of primary rhabdoid melanoma of the urinary bladder treated with ipilimumab, an anti-CTLA 4 monoclonal antibody

Primary melanoma of the urinary bladder is a rare subentity of melanoma. The same applies for melanoma of the rhabdoid histopathologic phenotype. A female patient was initially diagnosed with melanoma of unknown origin caused by macroscopic lymph node metastasis in the left inguinal and parailiacal regions. Because of the extent of the disease, radical surgery could not be performed. The patient underwent systemic chemotherapy with dacarbazine, followed by the experimental compound tasisulam. Upon sudden macrohematuria, cystoscopy showed a large infiltrating tumorous structure located on the left side of the urinary bladder. Clinically, the amelanotic tumor showed endophytic growth into the lumen; on the histopathological specimen, the growth pattern was partially undermining the urothelium, which is commonly observed in primary melanoma of the urinary bladder. Cytologically, the tumor cells were classified as rhabdoid melanoma, a very rare variant of melanoma, which is commonly amelanotic and expresses S100, vimentin and Ncam. Mutational analysis showed positive results for BRAF V600E. After detecting the primary melanoma, the patient received anti-CTLA4 antibody treatment with 3 mg/kg ipilimumab, through which a partial response was achieved. Past computed tomography scans should be re-evaluated for suspicious lesions, and cystoscopy should be included in the clinical workup if the pattern of metastasis is congruent with the drainage sites of the urinary bladder.

Urinary tract transitional cell carcinoma and melanosis of the bladder: a case report and review of the literature

Melanosis vesica is a rare condition and thought to be benign. We report the case of a 50-year-old man who presented with haematuria and was found to have a diffusely pigmented bladder on cystoscopy and high grade transitional cell carcinoma of his upper and lower renal tract. This required a laparoscopic nephroureterectomy and pathology confirmed a diagnosis of melanosis vesica. Melanosis vesica has only been associated with high grade transitional cell carcinoma in one previous case. We recommend that any patient presenting with bladder melanosis is monitored for the development of upper or lower urinary tract transitional cell carcinoma.