Primary malignant 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.

Mucosal Melanoma: Epidemiology, Clinical Features, and Treatment

PURPOSE OF REVIEW

Summarize the writings published in the last years on the management and novel therapies of mucosal melanoma (MM).

RECENT FINDINGS

New research has demonstrated a difference between MM and cutaneous melanoma (CM) in their genomic and molecular landscapes, explaining the response's heterogeneity. Immunotherapy and targeted therapy have limited benefit, but novel therapies are rapidly expanding. MM is aggressive cancer occurring in gastrointestinal, respiratory, or urogenital mucosa; whose incidence is greater in the Asian population. The etiology and pathogenesis remain unclear since UV exposure is not a proven risk factor as in cutaneous melanoma. In contrast to CM, lesions on the mucosal surface are less likely to be recognized early; therefore, the disease is diagnosed in an advanced stage. Clinical manifestations, such as bleeding or pain, can help to detect this tumor, although the prognosis remains unfavorable with an overall 5-year survival rate of less than 20%. The mutational landscape of MM includes mutations of BRAF and NRAS, as well as mutations in the c-KIT/CD117 gene (in 50% of patients), thus limiting therapeutic interventions to immunotherapy. However, clinical studies show less responsiveness to immunotherapy compared to CM, therefore novel therapeutic strategies targeting new molecules are needed to improve the survival of patients with MM.

Demographics, Clinical Characteristics and Survival Outcomes of Primary Urinary Tract Malignant Melanoma Patients: A Population-Based Analysis

All primary urinary tract malignant melanoma (ureter vs. bladder vs. urethra) patients were identified from within the Surveillance, Epidemiology, and End Results (SEER) database 2000-2020. Kaplan-Maier plots depicted the overall survival (OS) rates. Univariable and multivariable Cox regression (MCR) models were fitted to test the differences in overall mortality (OM). In the overall cohort (n = 74), the median OS was 22 months. No statistically significant or clinically meaningful differences were recorded according to sex (female vs. male; p = 0.9) and treatment of the primary (endoscopic vs. surgical; p = 0.6). Conversely, clinically meaningful but not statistically significant (p ≥ 0.05) differences were recorded according to the patient's age at diagnosis (≤80 vs. ≥80 years old; p = 0.2), marital status (married 26 vs. unmarried 16 months; p = 0.2), and SEER stage (localized 31 vs. regional 14 months; p = 0.4), and the type of systemic therapy (exposed 31 vs. not exposed 20 months; p = 0.06). Finally, in univariable and MCR analyses, after adjustment for the SEER stage and type of systemic therapy, tumor origin within the bladder was associated with a three-fold higher OM (Hazard ratio: 3.00; p = 0.004), compared to tumor origin within the urethra. In conclusion, primary urinary tract malignant melanoma patients have poor survival. Specifically, tumor origin within the bladder independently predicted a higher OM, even after adjustment for the SEER stage and systemic therapy status.

Epidemiology of Unconventional Histological Subtypes of Urethral Cancer

INTRODUCTION

The aim of the study was to examine cancer-specific mortality (CSM) of unconventional urethral cancers.

METHODS

Within the SEER (2004-2016) database, we analyzed CSM of 165 patients with unconventional urethral-cancer histology. Kaplan-Meier plots were used to test the effect of unconventional histologies in urethral cancer on CSM.

RESULTS

Of 165 eligible patients, the Mullerian type accounted for 55 (33.3%) versus melanocytic (26.7%) versus neuroendocrine 25 (15.2%) versus lymphoma 22 (13.3%) versus mesenchymal/sarcoma 15 (9.1%) versus spindle cell 4 (2.1%) patients. Median age at diagnosis was 81 years in spindle cell, 75 in melanocytic, 74 in neuroendocrine and mesenchymal/sarcoma, 67 in lymphoma, and 62 years Mullerian type (p < 0.001). Of all, 116 (70.3%) were female. The Mullerian type exhibited the highest female ratio (96.4%) versus the lowest female ratio in neuroendocrine (24.0%). The Mullerian type was most frequent in African-American females. In Caucasian females, the melanocytic type was most frequent (49.1%). In African-American (38.9%) and Caucasian males (33.3%), neuroendocrine histology was most frequent. Three-year CSM was, respectively, 27.5%, 23.1% 22.3%, 20.5%, and 16.1% for melanocytic, mesenchymal/sarcoma, Mullerian type, neuroendocrine, and lymphoma histology. Median cancer-specific survival was 106 versus 10 months for combined nonmetastatic versus metastatic nonconventional histologies.

CONCLUSION

Important age, sex, racial/ethnic group distribution, and survival differences exist between each unconventional urethral-cancer histological subtypes.

An Approach to Nonurothelial Malignancies of the Urinary Bladder in Urine Cytology

Urine cytology is an economical and convenient method of triaging patients who present with urinary symptoms as well as surveying those who have previously been diagnosed with urothelial carcinoma for recurrent or persistent disease. While the vast majority of malignancies diagnosed in urine cytology are urothelial carcinomas, it is important to recognize nonurothelial elements to inform patient prognosis and raise the possibility of involvement by a urothelial carcinoma variant, nonurothelial malignancy of the bladder, or a nonbladder primary, which may alter patient management pathways. As such, becoming familiar with morphologic features of nonurothelial malignancies in urine cytology as well as their related clinical risk factors, radiologic and cystoscopic features, differential diagnostic considerations, and the utility and pitfalls of ancillary tests can facilitate optimal patient care.

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.

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

Background

Primary melanoma of the 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 67-year-old female patient who presented with hematuria and was diagnosed with primary melanoma of the bladder by transurethral resection. No distant metastasis was detected by fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT). After a multidisciplinary discussion, the patient received laparoscopic radical resection of the bladder tumor. There was no tumor recurrence or distant metastasis after 15 months of follow-up.

Conclusion

Primary melanoma of the bladder is easily confused with urothelium carcinoma in morphology. The immunohistochemical is crucial in diagnosis. Because of a lack of in-depth understanding of primary melanoma of the bladder, the “gold standard” treatment has not been set. We would like to provide some rare information about it and discuss the proper treatment strategy for this rare disease.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02753-5.

Identification of distinct genomic features reveals frequent somatic AHNAK and PTEN mutations predominantly in primary malignant melanoma presenting in the ureter

BACKGROUND

Primary malignant melanoma of the ureter is extremely rare. Genetic variants to the increased risk of developing the disease have not yet been investigated.

METHODS

Tumour mutation profiling for primary malignant melanoma of the ureter was performed by whole-exome sequencing. Immunohistochemistry was performed to verify histopathological features and the variants of predisposing genes and driver mutation genes. Furthermore, we conducted a literature review and Surveillance, Epidemiology and End Result-based study by searching public databases.

RESULTS

We identified 38 somatic single nucleotide variants and 9 somatic insertions and deletions (INDELs) in tumour specimens. After filtering with the Cancer Gene Census database, seven predisposing genes and two driver mutation genes were identified. Moreover, the immunohistochemical profile showed that tumour cells were positive for Melan-A, melanoma gp100 human melanoma black 45 (HMB45), S100 beta and P53. The expression levels of two driver mutation genes (phosphatase and tensin homolog (PTEN) and desmoyokin (AHNAK) and five predisposing genes (AT-rich interaction domain 1B (ARID1B), catalase, eukaryotic translation initiation factor 4 gamma 3 (EIF4G3), ANK3 and collagen type I) were significantly downregulated in tumour tissues compared to paracancerous tissues. In the literature review and Surveillance, Epidemiology and End Results-based study, patients with primary malignant melanoma of the urinary tract had worse clinical outcomes than patients with primary urothelial carcinoma after 1:2 propensity score matching (P = 0.010). Additionally, Cox multivariate analysis for patients with primary malignant melanoma of the urinary tract indicated that distant metastasis (hazard ratio = 1.185; P = 0.044) was an independent predictor for overall survival, and tumour focality (hazard ratio = 0.602; P = 0.017) and non-surgery (hazard ratio = 0.434; P = 0.003) were independent factors for tumour progression.

CONCLUSIONS

Our study is the first to provide evidence that the distinct phenotypes of primary malignant melanoma of the ureter may be due to different genetic variations. The prognosis of primary malignant melanoma of the urinary tract was poorer than that of primary urothelial carcinoma of the urinary tract.

Primary Malignant Melanoma of the Bladder: A Rare Case Report in Asia and Review of the Literature

Background

Primary malignant melanoma (PMM) of the bladder is extremely rare and has a poor prognosis; just 40 cases of PMM of the bladder have been recorded in the literature. We described a case of PMM of the bladder, treatment, and a review of the literature because the recommended treatment choices are not widely known.

Case Presentation

An 80-year-old Thai female came in with a three-month history of pelvic pain and dysuria without extensive hematuria. She underwent transurethral excision of the bladder tumor and histologically reported malignant melanoma with no further primary sites of melanoma after computed tomography indicated a big heterogeneous enhancing mass on the posterior wall of the bladder. The patient eventually underwent anterior pelvic exenteration with ileal conduit, but metastatic disease occurred one year later.

Conclusion

Bladder melanoma has a fatal aggressive nature. Certain diagnostic features can be obtained through histopathological investigation, immunohistochemistry, clinical history, and endoscopic evaluation. Despite a wide range of treatments, people with PMM still have a bad prognosis.

Multimodality Imaging and Genetics of Primary Mucosal Melanomas and Response to Treatment

Mucosal melanomas (MMs) are rare and aggressive tumors that arise from melanocytes in the mucosal tissues that line the respiratory, gastrointestinal, and urogenital tracts. Most MMs occur during the 6th and 7th decades of life. MMs may be asymptomatic but may also cause bleeding, pain, and itching, depending on the site of origin. Because of their asymptomatic or oligosymptomatic nature and the difficulty of visualizing them in some cases, they are often advanced tumors at patient presentation. MM staging varies depending on the site of the primary tumor. A simplified staging system allows classification of clinically localized disease as stage I, regional nodal involvement as stage II, and distant metastasis as stage III. MM differs genetically from its cutaneous counterparts. Common drivers in cutaneous melanoma such as B-raf proto-oncogene serine/threonine kinase (BRAF) have a lower mutation rate in MM, whereas mutations of other genes including the KIT proto-oncogene, receptor tyrosine kinase (KIT) and splicing factor 3b subunit 1 gene (SF3B1) are more common in MM. Complete resection is the best curative option. However, surgical intervention with wide local excision and negative margins may be difficult to attain because of the local anatomy and the extent of disease. In addition, despite aggressive surgical resection, most patients develop local recurrence and metastatic disease. Recent advances in the treatment of melanoma include immunotherapy and targeted therapy. Unfortunately, MMs have a relatively poor prognosis, with an overall 5-year survival rate of 25%. Online supplemental material is available for this article. ^©RSNA, 2021.

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.

High-grade Urothelial Carcinoma with Malignant Melanocytic Differentiation

Urothelial carcinoma usually shows divergent differentiation and variant histology with squamous and glandular morphology being most common. In this report, we present a case of divergent malignant melanocytic differentiation in a high-grade urothelial carcinoma. A 98-year-old East Asian woman with an anterior bladder wall mass underwent resection, which revealed a high-grade poorly differentiated tumor. A minor component of high-grade papillary urothelial carcinoma and carcinoma in situ is also present. The majority of the tumor cells are morphologically and immunohistochemically consistent with melanoma, a minority of cells are positive for urothelial markers, and rare cells coexpress both melanocytic and urothelial markers. Cells that express melanocytic markers or urothelial markers are intimately admixed together. Taken together, a diagnosis of high-grade urothelial carcinoma with malignant melanocytic differentiation was rendered. This is the first report in the literature of malignant melanocytic differentiation in a high-grade urothelial carcinoma, a finding that may have important diagnostic and therapeutic implications.

Melanosis of bladder: A rare entity

Melanosis of the bladder, also known as melanosis vesicae, refers to presence of pigment in bladder mucosa. A rare phenomenon, however, it can be confused with the primary or metastatic melanoma of the bladder. Therefore, knowledge of the entity can prevent over diagnosis of this benign entity.

We are reporting a case of melanosis of bladder in a 69 year old male with prolonged history of LUTS and bladder diverticulae. Cystoscopic examination showed black patches and biopsy revealed pigmentation in the epithelium and underlying lamina propria. Special stains identified the pigment to be melanin. No malignant cells were identified.

PRIMARY MALIGNANT MELANOMA OF THE URINARY BLADDER: CASE REPORT

Primary malignant melanoma of the urinary bladder is rare, with only 20 cases reported to date. We present a case of an 87-year-old woman with multiple comorbidities who presented with advanced urinary bladder neoplasm. Histopathologic analysis suggested melanoma of the urinary bladder. No previous or concurrent diagnosis of cutaneous melanoma was documented. The patient underwent transurethral resection of the tumor before and during hospitalization at our hospital but died shortly after due to widespread disease. Autopsy was not performed.

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.

Metastatic Melanoma to the Urinary Bladder of Ocular Origin Accompanied with Primary Cutaneous Melanoma: Diagnostic Challenge-A Report of a Case

Metastases of melanoma to the urinary bladder are infrequent. Even rarer are metastases to the urinary bladder from uveal melanoma, with only 3 cases published in the literature so far. Herein we present a case of a 77-year-old male patient who presented with metastatic melanoma to the urinary bladder. The patient's history included the diagnoses of uveal melanoma treated with radiation 25 years ago, as well as that of cutaneous melanoma diagnosed 7 years ago. The molecular study of the urinary bladder tumor specimen identified mutation of the GNAQ gene, which has been suggested to be an early molecular event in the pathogenetic course of over 80% of uveal melanomas. Therefore, the diagnosis of uveal melanoma metastatic to the urinary bladder was made.

Mucosal melanomas in the elderly: challenging cases and review of the literature

Melanomas are malignant tumors that originate from melanocytes. They are most frequently localized in the skin, but 5% of all melanomas interest also extracutaneous sites as mucosal surfaces, parenchymatous organs, the retroperitoneum area, and the ocular ball. The purpose of this study was to investigate the epidemiologic and morphologic data of mucosal melanomas diagnosed at Emergency City Hospital (Timisoara, Romania) during a period of 12 years. The study included 17 cases of extracutaneous, extraocular melanomas, with 16 primary melanomas and one secondary melanoma. All our patients were older than 53 years and were mostly men. Most of the patients presented with localized disease; only one case had regional lymph node metastases, and another one had systemic metastases at the time of diagnosis. Regarding localization, nine of 16 melanomas were in the head and neck region, six were diagnosed in the gastrointestinal and urogenital tracts (three cases each), and one case had a rare localization (retroperitoneum). The most common histologic type was represented by epithelioid cells, and the majority of the tumors were achromic. Mucosal melanoma is a tumor associated with aging, all our patients being older than 53 years. Because of unspecific symptoms and low incidence, the diagnosis is often delayed and requires teamwork among the clinician, pathologist, radiologist, and oncologist. Different genetic fingerprints impose a correct diagnosis to offer the patient the best novel, personalized therapy.

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.

A Case Report of Primary Recurrent Malignant Melanoma of the Urinary Bladder

Primary malignant melanoma of the urinary bladder is a rare neoplasm, with only 19 cases reported to date. We present a case report of an 84-year-old woman who underwent transurethral resection of a mucosal melanoma of bladder origin. She had no previous or concurrent diagnosis of cutaneous melanoma. The patient underwent transurethral resection of the tumor 5 months before presentation at our center with a recurrent, muscle-invasive tumor located in the bladder trigone, with evidence of bone metastasis. Malignant melanoma of the urinary bladder carries a poor prognosis and poses a therapeutic challenge to urologists who manage patients with this rare disease.

Langerhans cell histiocytosis of the urinary bladder in a patient with bladder cancer previously treated with intravesical Bacillus Calmette-Guérin therapy

We report an extremely rare case of Langerhans cell histiocytosis (LCH) of the urinary bladder. A 68-year-old man presented with gross hematuria. Cystoscopy showed multiple papillary tumors in the urinary bladder, and transurethral resection was performed. Pathological diagnosis was high-grade papillary urothelial carcinoma with lamina propria invasion. The patient received six treatments with intravesical Bacillus Calmette-Guérin (BCG) therapy. Seven months after surgery, follow-up cystoscopy showed three elevated lesions in the urinary bladder, two of which were identified histologically as recurrent urothelial carcinoma. Microscopic examination of the lesion at the anterior wall revealed diffuse infiltration of medium to large histiocytoid cells in the lamina propria, many of which had distorted nuclei and nuclear grooves. Dense eosinophilic infiltration was also observed. Immunohistochemically, the histiocytoid cells were diffusely positive for S-100 and CD1a, but negative for cytokeratin AE1/AE3 and melanosome-associated antigen recognized by HMB-45. Based on the histological and immunohistochemical features, we diagnosed the lesion as LCH of the urinary bladder. There was no evidence of recurrence of either bladder cancer or LCH after an 18-month follow-up. To avoid misdiagnosis, urologists and pathologists should be aware that LCH may develop in the urinary bladder after intravesical BCG therapy for bladder cancer.

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.

Primary malignant melanoma of the urinary bladder

Introduction. Primary melanoma of the urinary bladder is very rare. As far as we know, 19 cases have been reported worldwide, usually as case reports. Case Presentation. We present a 71-year-old male patient presented with a 2-month history of hematuria. Ultrasonography revealed a 5-cm-size mass located in the bladder trigone. A transurethral resection of the bladder tumor (TURBT) revealed a malignant melanoma. Evaluation for metastatic disease was negative. The patient deceased five months later before radical treatment could be performed. Conclusion. This is one more reported case of primary melanoma of the urinary bladder. The previously reported cases of bladder melanoma are reviewed. Therapy and prognosis are discussed.