Malignant melanoma of the genitourinary tract

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.

Metastatic Melanoma to the Urinary Bladder: A Rare Cause of Visible Haematuria

Bladder metastasis from cutaneous melanoma is a rare pathology. A 79-year-old woman presented to the haematuria clinic on account of painless visible haematuria. Ten years prior to this index presentation, she was diagnosed with melanoma on her right thigh following a total excision of the skin lesion. Cystoscopy showed a pigmented bladder tumour, and the histology report following a transurethral resection was consistent with metastatic melanoma, and further imaging revealed metastasis to the lungs, adrenals, and lymph nodes.

Primary malignant melanoma of the genitourinary tract: case series of a rare form of primary mucosal melanoma

Primary malignant melanoma of the genitourinary tract is extremely rare. We present two such cases in elderly Caucasian females. An 81-year-old female with urinary retention and polypoid urinary bladder mass and a 72-year-old female with gross hematuria and urethral caruncle. After thorough evaluation, they were both eventually diagnosed with primary urogenital melanoma (SOX10 and MART1-positive in tumor cells). In both cases, the presence of melanoma-in-situ and absence of primary melanoma in other sites were consistent with primary urogenital melanoma. Immunotherapy with PD-1 inhibitors and use of neoadjuvant and adjuvant treatment are promising, as treatment guidelines remain unclear and overall survival is low. Additional clinical reporting of primary urogenital melanomas can help in better understanding and ultimately treating it.

Melanosis of the urinary bladder

Melanosis bladder refers to the urothelium of the bladder appearing black and velvety, with microscopic evaluation describing melanin deposition. Risk factors, pathogenesis and clinical implications are unknown because only sporadic cases are reported in the literature, both with and without the presence of urinary tract symptoms or malignancy. We report a case of melanosis bladder in a male patient with voiding urinary symptoms and an untreated hypospadias.

Melanoma metastasis to the bladder: A case report

Metastasis of malignant melanoma to the bladder is rarely seen clinically with only 29 cases reported in English-language literature. However, autopsy series of melanoma patients have shown that metastasis to the bladder could be as high as 37%, implying that numerous cases remain undiagnosed. This report details a case of malignant melanoma metastasis to the bladder. Patient presented with severe anemia and history of gross hematuria. Computerized tomography (CT) revealed a 2.7 cm mass in the bladder. Cystoscopy confirmed presence of a mass. Patient underwent cystoscopy and transurethral resection of the tumor, revealed to be melanoma on pathology.

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.

Malignant melanoma of the prostate gland: A systematic review

AIMS

Prostatic melanoma is a rare malignancy about which only scattered case reports and no systematic reviews have been published to date. We sought to better inform clinicians and pathologists caring for these patients by gathering all available evidence on the topic.

METHODS

We performed a systematic review of English and non-English articles indexed in PubMed, EMBASE, Scopus and Google Scholar about primary and metastatic prostatic melanoma.

RESULTS

In total, 25 studies describing 45 cases were identified. Most cases were metastases to the prostate, with only 10 primary prostatic cases. The median age of patients was 61 years with a wide range, and 89% were symptomatic at presentation, most commonly with obstructive symptoms (83%). Diagnosis requires histopathological analysis and often immunohistochemistry. Metastatic melanoma in the prostate carries a dismal prognosis with median overall survival of 3 months; on the other hand, among primary prostatic melanomas reported in the literature, 29% survived longer than 5 years. The most reasonable therapeutic approach consists in radical surgery possibly followed by adjuvant therapy.

Metastatic melanoma to the bladder presenting as autonomic dysreflexia in a patient with paraplegia

We report a case of a 66-year-old male with T2 American Spinal Injury Association Impairment Scale (AIS) A paraplegia who presented to Urology with worsening autonomic dysreflexia. Work-up identified a bladder mass treated by transurethral resection and pathologically confirmed as melanoma. Additional work-up revealed metastatic melanoma to the back and brain. The patient completely recovered with no evidence of disease more than two years after completing therapy. In this report, we review the presentation of metastatic bladder melanoma presenting with autonomic dysreflexia, which has never been previously described, and discuss the prognosis of metastatic melanoma to the bladder.

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.

Cutaneous malignant melanoma with rarest combination of prostatic and splenic metastases on fluorodeoxyglucose (FDG) positron emission tomography-computed tomography scan

Cutaneous malignant melanoma (MM) metastases to prostate and spleen are very rarely experienced in clinical setting. As per our knowledge, coexistence of prostate and splenic metastatic MM is not reported worldwide. We are presenting a case of 70-year-old male patients with biopsy and clinically proven case of multifocal cutaneous malignant melanomatous lesions having multiple metastatic lymph nodes and systemic metastases, including prostate and spleen. This is the first case reported worldwide having a combination of prostate and splenic metastases.

Urinary bladder metastasis from malignant melanoma

Bladder metastases from malignant melanoma are very rare, with only about 30 cases reported to date. They are often associated with synchronous metastases elsewhere in the body and portend poor prognosis. Herein, we present the case of a 62-year-old man with a history of two completely resected, non-node-metastatic cutaneous malignant melanomas who presented with gross haematuria as his only symptom. We then proceed to discuss the diagnostic process and prognostic implications of primary and metastatic malignant melanomas of the urinary bladder.

Level of evidence: 5

A rare cause of acute urinary retention- Primary malignant melanoma of prostate

Acute urinary retention is commonly seen in elderly male patient due to benign enlargement of prostate. We report a 65-year-old male presenting with acute urinary retention diagnosed to have primary malignant melanoma of prostate. Primary malignant melanoma of genitourinary tract is very uncommon diagnosis in urology and prostate involvement is extremely rare. Till now only five cases have been reported.

Malignant Melanoma of the Penis. A Report of Four Cases

Malignant melanoma (MM) of the penis is a rare neoplasia. We report 4 cases by a retrospective survey of all cases of MM observed at the Istituto Nazionale Tumori of Milano from 1967 to 1988. The problem of the therapeutic approach is still unsolved. Therefore, any case is useful for a better knowledge of the natural history of this disease.

Metastatic Melanoma to the Bladder: Case Report and Review of the Literature

A 49-year-old Caucasian woman presented to the dermatology clinic for follow-up of malignant melanoma with a complaint of painless gross hematuria. Two years prior she was diagnosed with malignant melanoma from a skin lesion on her left flank treated with wide excision, negative axillary sentinel lymph node biopsy, and adjuvant radiotherapy. Subsequently, she had no evidence of disease until urologic evaluation of her hematuria revealed two lesions in her bladder and cytopathology demonstrated findings consistent with malignant melanoma. We review literature on melanoma metastatic to the bladder and discuss the potential role of metastasectomy and other treatment strategies in such rare cases.

Primary Malignant Melanoma of Renal Pelvis with Extensive Clear Cell Change

Our presentation illustrates a rare case of primary renal pelvis malignant melanoma in a 35-year-old man. The diagnosis of malignant melanoma was based on immunophenotype and the detection of intracellular melanin pigment. The renal origin was proven by the presence of scattered melanocytes within the urothelium of the pelvis. The tumor exhibited extensive clear cell change that closely mimics clear cell renal cell carcinoma. The patient's clinical history did not disclose any signs of previous melanocytic skin or mucosa lesions. Differential diagnosis includes tumors capable of synthesizing melanin or expressing melanocytic markers.

Metastasis of Malignant Melanoma to Urinary Bladder: A Case Report and Review of the Literature

Aims. Metastatic malignant melanoma of the urinary bladder is a rare clinical entity, with only twenty-three published cases to date. We present a case of this rare entity, a thorough review of the literature, and differential diagnosis of melanoma in the bladder. Methods and Results. A 55-year-old woman with a history of malignant melanoma of the right thigh, excised eight years ago, presented with back pain, fatigue, and hematuria. She underwent computed tomography (CT) scan and was found to have metastases within the liver, spleen, lungs, and urinary bladder. She underwent cystoscopy and transurethral resection of three polypoid lesions. Histologic and immunohistochemical examination revealed metastatic malignant melanoma involving bladder mucosa. Conclusions. This case illustrates the importance of including malignant melanoma in the differential diagnosis of high grade neoplasms of bladder, especially in cases where the relevant clinical history is not available.

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 of benign vesica melanosis – four-year follow-up

Benign vesica melanosis (BVM) is a rare condition with only 15 reported cases in the literature (Table 1). There is limited understanding of its aetiology. Here we present a four-year follow-up of a case of BVM in a 53-year-old Caucasian male presenting with lower urinary tract symptoms.

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.

Primary malignant melanoma of prostate

Primary genitourinary melanoma accounts for less than one per cent of all cases of melanoma. Most cases attributed to the prostate actually originate from the prostatic urethra. Due to its infrequency, primary malignant melanoma of the genitourinary tract presents a difficult diagnostic and management challenge. We report a case of primary malignant melanoma of the prostate found during transurethral resection of the prostate.

Primary melanoma of the adrenal gland: a case report and review of the literature

BACKGROUND

Primary melanoma of the adrenal gland is exceptionally rare as demonstrated by the few cases reported in the medical literature, and it has a high fatality rate. We present the case of a patient with two relapses and survival to date.

CASE REPORT

We describe the case of a 58-year-old Caucasian woman who consulted her doctor with symptoms of asthenia, anorexia and weight loss. A mass was palpated in her abdomen at the height of the left hypochondrium. A computed tomographic scan revealed a retroperitoneal mass measuring 10 cm × 15 cm originating in the left adrenal gland. A left nephroadrenalectomy and splenectomy were performed. Histopathologically, the retroperitoneal mass corresponded to a melanoma, and no primary melanoma was found in any other location. The patient was treated with interferon-α-2b. Three years after her diagnosis the patient presented with a retroperitoneal relapse of the mass measuring 7.2 cm, which was removed. Five years after the first relapse a new retroperitoneal relapse mass was diagnosed, which was also removed. Since then the patient has been healthy and free from illness.

CONCLUSION

Histological and immunohistochemical studies, together with the criteria described by Ainsworth et al. and Carstens et al., allowed us to diagnose primary melanoma of the adrenal gland.

A renal mass in a patient with melanoma

A 61-year-old man presented to the emergency room with significant weight loss. Laboratory analysis revealed elevations in blood urea nitrogen, creatinine, and white blood cell count. Computed tomography imaging showed a large, infiltrative mass in the right renal vein, with metastasis to the brain. Biopsy of soft tissue mass and kidney revealed positive staining for malignant melanoma. Malignant melanoma to the kidney is extremely rare, and imaging modalities alone cannot differentiate neoplasms in the kidney. It is therefore necessary to use specific immunocytochemical staining along with imaging modalities to make a specific diagnosis when the primary origin of the tumor is unknown.

Melanotic Xp11 translocation renal cancers: a distinctive neoplasm with overlapping features of PEComa, carcinoma, and melanoma

We describe 2 cases of malignant melanotic epithelioid renal neoplasms bearing TFE3 gene fusions. Both neoplasms occurred in children (an 11-y-old boy and a 12-y-old girl), and presented with disseminated metastatic disease including mediastinal and mesenteric adenopathy. Both neoplasms featured sheets of epithelioid cells with clear to finely granular eosinophilic cytoplasm set in a branching capillary vasculature. The neoplastic cells contained variable amounts of finely brown pigment confirmed to be melanin by histochemical stains. By immunohistochemistry, the neoplastic cells labeled for melanocytic markers HMB45 and Melan A, but not for S100 protein, MiTF, or any epithelial marker (cytokeratins, epithelial membrane antigen), renal tubular marker (CD10, PAX8, PAX2, RCC Marker) or muscle marker (actin, desmin). Both neoplasms demonstrated nuclear labeling for TFE3 protein by immunohistochemistry, and the presence of TFE3 gene fusions was confirmed by TFE3 fluorescence in situ hybridization analysis. These distinctive neoplasms combine morphologic features of perivascular epithelioid cell neoplasms (PEComas), Xp11 translocation carcinoma, and melanoma, though the phenotype most closely approaches PEComa. These neoplasms represent the first documented examples in which TFE3 gene fusions coexist with melanin production, and their identification raises the possibility that TFE3 gene fusions may underlie an aggressive subset of lesions currently classified as PEComa in young patients.

High-grade transitional cell carcinoma and melanosis of urinary bladder: case report and review of the literature

Melanosis of the urinary bladder is a rare entity. It is generally regarded as a benign condition, but it is sometimes associated with primary malignant melanoma of the urinary bladder. It has never been reported to be connected with transitional cell carcinoma. We present a case of a woman with melanosis of the bladder who a year later developed high grade transitional cell bladder carcinoma.

Malignant melanoma of the scrotum

Malignant melanoma of the scrotum is the rarest of primary genitourinary melanomas, with only 17 cases having been reported between 1949 and 2005. We report one such case, which presented as a nonhealing ulcer over the right hemiscrotum.

Prognosis of Primary Mucosal Penile Melanoma: A Series of 19 Dutch Patients and 47 Patients from the Literature

OBJECTIVES

To analyze the clinical features, prognostic factors, and survival of male patients with primary mucosal melanoma on the glans penis, meatus, fossa navicularis, and distal urethra.

METHODS

We analyzed the clinical features, prognostic factors, and survival of 66 male patients with primary mucosal melanoma on the glans penis, meatus, fossa navicularis, and distal urethra diagnosed over the past 25 years. Data from our series of 19 patients were combined with those of 47 patients reported in the literature.

RESULTS

The overall 2 and 5-year survival rates were 63% and 31%, respectively. All patients with nodal and/or distant metastases at presentation died within 2 years. Presence of ulceration, tumor depth of 3.5 mm or more, and tumor diameter greater than 15 mm had a significantly adverse effect on prognosis.

CONCLUSIONS

The prognosis of primary mucosal penile melanoma is not worse than that for cutaneous melanoma with comparable tumor thickness. Treatment should be similar to that for cutaneous melanoma, with wide radical excision and sentinel node biopsy in clinically lymph node-negative patients.

Renal metastasis of malignant melanoma with unknown primary

The kidney is a common location for micrometastases in patients with malignant melanomas. These lesions are usually small, multiple, asymptomatic, and bilateral, and associated with a known primary lesion. This is an unusual case of a 38-year-old woman, with no history of melanoma, presenting with an asymptomatic solitary renal mass and two lung masses. She was doing well 3 months after laparoscopic radical nephrectomy and one course of interleukin-2 therapy.

Primary mucosal melanoma

Primary mucosal melanomas are rare, biologically aggressive neoplasms. The distribution of head and neck, female genital tract, anal/rectal, and urinary tract sites is 55.4%, 18.0%, 23.8%, and 2.8%, respectively. The median age at presentation is the seventh decade, and women are given the diagnosis more frequently than men. Unfortunately, most afflicted individuals harbor micrometastatic disease and experience a course characterized by multiple local recurrences before the clinical development of distant disease. Approximately a third of patients have nodal involvement at presentation, and the overall 5-year survival is only 25%. Despite aggressive surgical resection and a multitude of adjuvant treatments, the prognosis remains grave. Early detection, which is difficult because of the occult anatomic locations in which these tumors occur, allows the best hope for cure.

Melanosis of the bladder: a rare endoscopic and histopathological finding

Melanosis of the bladder represents a rare condition characterized by anomalous deposits of melanin-containing pigment. To our knowledge, so far, just 5 cases have been reported in the literature. We describe a case of a simply melanosis of the bladder confirmed by histochemical stains and immunohistochemistry analysis.

Primary malignant melanoma of the bladder

Primary malignant melanomma of bladder is extremely rare: 18 cases are reported to date. An 82 year-old man underwent trans-urethral resection of bladder for a bleeding tumor of the posterior wall. Histological diagnosis was melanoma of the bladder. There was no history of previous or regressed cutaneous malignant melanoma. Margins of the bladder lesion contained atypical melanocytes similar to those commonly seen in the periphery of primary mucous membrane lesions. Clinical studies and radiological examinations were negative for other primary site of melanoma. The patient had a bladder recurrence that was consistent with primary tumor and died of widespread disease 9 months after diagnosis.

Metastatic ocular melanoma to the kidney 20 years after initial diagnosis

Metastatic tumors are the most common malignancies of the kidney. We report a rare case of isolated metastatic ocular melanoma to the kidney occurring 20 years after diagnosis. A 71-year-old man presented with gross hematuria. He had undergone left enucleation 20 years previously for ocular melanoma and had not required adjuvant therapy. A right upper pole mass was identified on computed tomography and was excised laparoscopically. Pathologic examination revealed metastatic melanoma. Metastatic melanoma to the kidney is rare. A high index of suspicion must be maintained in any patient with a renal mass and a history of a nonrenal malignancy.

Recurrent primary vulvovaginal malignant melanoma arising in melanoma in situ--the natural history of lesions followed for 23 years

Multifocal melanoma and melanoma in situ of the vulva and vagina are uncommon lesions, and our understanding of their natural history is limited. Vulvovaginal melanoma appears to be biologically different from cutaneous melanoma and has more in common with mucosal melanoma. A 60-year-old woman presented in 1977 with a pigmented vulvar lesion. Histologic examination revealed melanoma in situ associated with focal invasive melanoma. She re-presented with recurrent primary melanomas arising in melanoma in situ in 1990 and 1998 and died of widespread metastatic melanoma in 2000. Melanoma in situ of the vulva and vagina is rare and appears to have a relatively slow but definite progression to invasive melanoma. All suspicious pigmented lesions in this region should be biopsied, and if multifocal in situ melanoma is identified, vulvo(vagin)ectomy should be considered.

Pigmented lesions in unusual anatomic sites

This review considers pigmented melanin-containing lesions arising in extracutaneous locations. It includes reactive lesions as well as benign and malignant neoplasms. Melanocytic lesions of the mucosae, nervous system, and individual organs are discussed, and rarer pigmented tumors in unusual sites are also covered. A brief description of the histology and clinical behavior along with proposed explanations for their ectopic location are provided. Emphasis is given to the reality that detailed morphological evaluation and application of ancillary techniques can establish the melanocytic nature and biologic potential of such tumors, but cannot, by themselves, determine the primary or metastatic nature of these lesions.

Management of metastatic malignant melanoma of the bladder

Recombinant interleukin-2 (IL-2) has demonstrated antitumor activity and durable clinical responses in patients with metastatic melanoma. Careful screening and selection of appropriate patients has improved the safety profile of IL-2 administration. Gross hematuria would ordinarily preclude the safe delivery of IL-2. We report a case of metastatic melanoma to the bladder presenting with hematuria. A complete resection was performed and subsequently allowed the administration of high-dose, bolus IL-2. The combination of resection and IL-2 therapy resulted in a partial response maintained for more than 18 months. Symptomatic bladder melanoma should be aggressively treated to allow for systemic immunotherapy, which can provide durable responses.

Vulvar melanoma: a retrospective analysis and literature review

OBJECTIVE

This review focuses on current directions in the staging and treatment of melanoma of the vulva.

METHODS

All women treated for invasive melanoma of the vulva at the University of Virginia Health Sciences Center from 1980 through 2000 were identified through a retrospective review of the records of the Division of Gynecologic Oncology. Their treatments and outcomes were then analyzed and presented.

RESULTS

Over the 20-year study period, 14 cases of melanoma of the vulva were identified. Of the 14 patients treated with curative intent, 6 developed recurrences following the completion of primary therapy, and all are dead from their disease. The mean duration from completion of therapy to recurrence was 7.5 months; the mean survival following recurrence was 17 months.

CONCLUSION

One-centimeter skin margins appear adequate for vulvar melanomas <1 mm thick, and 2-cm margins appear adequate for intermediate-thickness melanomas (1-4 mm). In all cases it is necessary to include at least a 1-cm-deep margin extending through the subcutaneous fat to the muscular fascia below. Elective node dissection seems to offer no additional advantage in superficial lesions <0.76 mm thick, and its role in deeper lesions is still uncertain.

Primary genitourinary melanoma

OBJECTIVES

To describe the presentation, management, and clinical outcome of patients with genitourinary melanoma.

METHODS

We identified 14 patients with genitourinary melanoma treated at Memorial Sloan-Kettering Cancer Center, New York and Tripler Army Medical Center, Honolulu, Hawaii. The presentation, surgical treatment, disease progression, and outcome of these patients were reviewed. Survival was analyzed, using the Kaplan-Meier product limit method.

RESULTS

The presentation and management of patients with genitourinary melanoma were varied. Overall, the prognosis was poor, with a median survival of 43 months, and only 3 patients were alive, without disease, at last follow-up. Our findings confirm a poor prognosis in patients with this rare disease.

CONCLUSIONS

Genitourinary melanoma is a rare form of the disease with an unfavorable clinical outcome. Less than one third of patients survive long term, although patients with scrotal melanomas may have a better prognosis.

Primary malignant melanoma of the male urethra

BACKGROUND

We describe a rare case of malignant melanoma originating from the male urethra.

METHODS/RESULTS

This case, which presented a tan-colored lesion at the distal urethra on urethroscopy, was considered as transitional cell carcinoma by transurethral biopsy. Pathologic examination of widely resected urethra revealed scattering cells, which included melanin granules in cytoplasm, and then immunohistochemical stains established the diagnosis as amelanotic melanoma. Although partial penectomy and inguinal lymph node dissection were subsequently performed, 7 months later, total cystourethrectomy was required because of multifocal recurrence at the residual urethra.

CONCLUSIONS

In cases of amelanotic melanoma, it should be noted that a lack of melanin granules in tumor cells may lead pathologists and urologists to a misdiagnosis due to the histologic non-specific appearance. With respect to surgical management, of significance is the fact that malignant melanoma may progress multifocally along the total urethra; therefore, total urethrectomy should be considered as radical surgery for the primary site, even if the tumor is confined to the distal urethra.

Primary malignant melanoma of the urethra: a clinicopathologic analysis of 15 cases

The clinical and pathologic features of 15 primary urethral melanomas occurring in patients (nine women and six men) age 44 to 96 years (mean age, 73 yrs) are described. In the men the tumor involved the distal urethra. In eight women it involved the distal urethra, usually the meatus; both the distal and proximal urethra were involved in one woman. The tumors were typically polypoid and ranged from 0.8 to 6 cm (mean, 2.6 cm) in maximum dimension. A vertical growth phase was present in all tumors, with a prominent nodular component in seven of them. A radial growth phase was seen in nine tumors. The depth of invasion ranged from 2 to 17 mm. The tumors had diffuse, nested, storiform, or mixed growth patterns. The neoplastic cells typically had abundant eosinophilic cytoplasm, large nuclei with prominent nucleoli, and brisk mitotic activity. Melanin pigment was seen in 12 tumors but was conspicuous in only six. At the time of diagnosis, 13 tumors were confined to the urethra and two patients had lymph node metastasis. Nine patients died of disease 13 to 56 months after initial diagnosis and treatment, and one patient had a local recurrence at 4 years and subsequently died of sepsis 1 year later. Three patients were alive and well at 11 months, 23 months, and 7 years. One patient died at the time of the initial operation, and one died of a ruptured aortic aneurysm at 3 years without evidence of melanoma at autopsy. Primary malignant melanomas of the urethra, one fifth of which are amelanotic, must be included in the differential diagnosis of a number of primary neoplasms that involve the urethra, including transitional cell carcinoma, sarcomatoid carcinoma, and sarcomas. Conventional prognostic factors, such as depth of invasion or tumor stage, do not seem to play as important a role in predicting survival as the mucosal location and the nodular growth present frequently in these tumors.

Secondary neoplasms of the bladder are histological mimics of nontransitional cell primary tumours: clinicopathological and histological features of 282 cases

AIMS

The incidence, anatomical localization and histological appearances of secondary neoplasms of the urinary bladder are described, with emphasis on the points of distinction from primary tumours.

METHODS AND RESULTS

A retrospective study of cases at the Royal Hospitals Trust yielded a total of 282 secondary bladder neoplasms, representing 2.3% of all malignant bladder tumours in surgical specimens. The commonest primary sites were the colon (21% of secondary neoplasms), prostate (19%), rectum (12%) and cervix (11%). Most tumours from these sites reached the bladder by direct spread. The most common sites of origin of tumours metastatic to the bladder were stomach (4.3% of all secondary bladder neoplasms), skin (3.9%), lung (2.8%), and breast (2.5%). Secondary tumour deposits were almost always solitary (96.7%), and 54% were located in the bladder neck or trigone. Histologically, 54% of secondary tumours were adenocarcinomas. Immunohistochemical staining patterns with prostate-specific acid phosphatase, prostate-specific antigen, carcinoembryonic antigen, chromogranin and neurone-specific enolase were similar in primary vesical and urachal adenocarcinomas and secondary adenocarcinomas from the gastrointestinal tract.

CONCLUSIONS

The incidence of secondary bladder tumours is comparable to that of nontransitional cell primary tumours. Few secondary tumours have distinctive histological features, hence knowledge of the history and clinical investigations are particularly important in their diagnosis.