Primary melanoma of the urinary tract; Clinicopathologic and molecular review of a case series

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.

Unusual presentation of metastatic melanoma

Urinary bladder with concurrent colonic melanoma is an exceptionally uncommon occurrence, posing a diagnostic challenge for clinicians. While rare, it warrants consideration as a potential differential diagnosis, particularly in patients without a history of melanoma who present with persistent hematuria due to its aggressive nature. We present a case of a 55-year-old female with malignant melanoma involving the colon and urinary bladder presenting with hematuria. Given the scarcity of cases and variability in clinical management approaches, there is a pressing need for research efforts to establish standardized protocols and conduct trials to guide clinical practice in this rare entity.

Primary metastatic melanoma of the female urethra: A case report and literature review

BACKGROUND

Urethral malignant melanoma is an uncommon and aggressive malignancy, frequently diagnosed at an advanced stage, posing diagnostic and therapeutic challenges.

CASE PRESENTATION

We present the case of a 74-year-old North African female diagnosed with primary metastatic urethral melanoma. Initial staging included a thorough physical examination, pelvic MRI, and whole-body CT scan, initially showing no signs of distant metastasis. Subsequent FDG PET/CT revealed unexpected bone metastases, prompting a significant shift in our management approach. The patient received immunotherapy with pembrolizumab, resulting in sustained metabolic stability at the six-month follow-up.

DISCUSSION

We present recent epidemiological data and risk factors for this uncommon melanoma site. Additionally, we delve into the diagnostic challenges, underlining the expanding role of PET/CT. The discussion also covers managing options in the absence of a consensus.

CONCLUSION

Despite several treatment choices, metastatic urethral melanoma still has a poor prognosis. This reality reflects the complexity of the disease and emphasizes the need for further research to unravel its underlying mechanisms and to establish more effective therapeutic approaches.

Malignant melanoma located in the ureter and gallbladder: A case report and literature review

RATIONALE

Melanoma is one of a common cutaneous malignancy. Currently, metastatic malignant melanoma is difficult to be diagnosed through imaging examinations. Furthermore, the incidence of metastatic melanoma affecting the gallbladder and ureter is exceptionally rare.

PATIENT CONCERNS

A 54-year-old female was admitted to the hospital with a half-month history of left lower back pain. Correlative examination revealed an occupying lesion in the mid-left ureter and the neck of the gallbladder.

DIAGNOSES

The patient was initially diagnosed with gallbladder cancer and left ureteral carcinoma based on imaging. Following 2 operations, immunohistochemical staining confirmed the presence of metastatic melanoma involving both the gallbladder and ureter.

INTERVENTION

After multidisciplinary consultation and obtaining consent from the patient and her family, the patient underwent left radical nephroureterectomy, radical cholecystectomy, laparoscopic partial hepatectomy (Hep IV, Hep V), and lymph node dissection of hepatoduodenal ligament.

OUTCOMES

One month after treatment, the patient imaging showed no disease progression, and at 6 months of follow-up, the patient was still alive.

LESSONS

It is difficult to distinguish metastatic melanoma from carcinoma in situ by imaging. In addition, metastatic malignant melanoma lacks specific clinical manifestations and is prone to misdiagnosis, which emphasizes the highly aggressive nature of malignant melanoma.

Primary malignant melanoma of the urethra: Report of 9 cases in China

BACKGROUND

Primary urethral melanoma is extremely rare and malignant, and accounts for <1% of all melanoma cases. Here, we aimed to gain more insight into the pathological and follow-up outcomes of patients with this tumor type.

METHODS

We conducted a retrospective analysis of nine patients who had undergone comprehensive treatment at West China Hospital since 2009. Furthermore, we also performed a questionnaire-based survey to determine the quality of life and health statuses of surviving patients.

RESULTS

Most participants were women, and their ages ranged between 57 and 78 years (mean age: 64.9 years). Common clinical presentations included pigmentation, moles, and irregular neoplasms in the urethral meatus with or without bleeding. The final diagnosis was based on pathological and immunohistochemical examination results. All patients underwent regular follow-ups after receiving surgical or non-surgical therapy, such as chemotherapy or radiotherapy.

DISCUSSION/CONCLUSION

Our study revealed that pathological and immunohistochemical tests are crucial for precise diagnosis, especially in asymptomatic patients. Primary malignant urethral melanoma generally has a poor prognosis; therefore, early and accurate diagnosis is imperative. Timely surgical intervention and immunotherapy can help improve patient prognosis. Moreover, an optimistic outlook and family support may augment the clinical management of this disease.

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.

Metastatic melanoma to the proximal ureter

We present an exceptionally rare scenario of obstructive uropathy secondary to a ureteral mass. This case details a 68-year-old female with metastatic stage IIID melanoma of the right heel found to have a two cm right proximal ureteral mass with associated hydronephrosis. Pathology from ureteroscopic biopsy revealed metastatic melanoma to the ureter, creating a unique treatment quandary.

Role of 18 F-FDG PET-CT in Urethral Malignant Melanoma and Analysis of the UK Guidelines on Ano-uro-genital Melanomas

Urethral melanomas are a rare subtype of noncutaneous melanomas. The disease has a tendency to have skip lesions and early metastases as compared with cutaneous melanomas. The role of fluorine-18 fluorodeoxyglucose ( 18 F-FDG) positron emission tomography computed tomography (PET-CT) is well established in cases of cutaneous melanomas and is recommended by the National Comprehensive Cancer Network (NCCN) for stage IIB to IV cancer. There are no established guidelines on the management of noncutaneous melanomas; however, a recently published United Kingdom national guideline aims to streamline the management of ano-uro-genital melanomas. The guideline describes a very limited role in the use of 18 F-FDG PET-CT in this case scenario. The tendency to skip lesions, early metastases, involvement of brain parenchyma, and finally the usage of anti-PD-1 medications are key areas where 18 F-FDG PET-CT has shown superiority over CT scan. With this case report, we aim to highlight the strength of 18 F-FDG PET-CT in the management of urethral melanomas, which can be extrapolated to other ano-uro-genital melanomas.

HOPX is a tumor-suppressive biomarker that corresponds to T cell infiltration in skin cutaneous melanoma

BACKGROUND

Skin cutaneous melanoma (SKCM) is the most threatening type of skin cancer. Approximately 55,000 people lose their lives every year due to SKCM, illustrating that it seriously threatens human life and health. Homeodomain-only protein homeobox (HOPX) is the smallest member of the homeodomain family and is widely expressed in a variety of tissues. HOPX is involved in regulating the homeostasis of hematopoietic stem cells and is closely related to the development of tumors such as breast cancer, nasopharyngeal carcinoma, and head and neck squamous cell carcinoma. However, its function in SKCM is unclear, and further studies are needed.

METHODS

We used the R language to construct ROC (Receiver-Operating Characteristic) curves, KM (Kaplan‒Meier) curves and nomograms based on databases such as the TCGA and GEO to analyze the diagnostic and prognostic value of HOPX in SKCM patients. Enrichment analysis, immune scoring, GSVA (Gene Set Variation Analysis), and single-cell sequencing were used to verify the association between HOPX expression and immune infiltration. In vitro experiments were performed using A375 cells for phenotypic validation. Transcriptome sequencing was performed to further analyze HOPX gene-related genes and their signaling pathways.

RESULTS

Compared to normal cells, SKCM cells had low HOPX expression (p < 0.001). Patients with high HOPX expression had a better prognosis (p < 0.01), and the marker had good diagnostic efficacy (AUC = 0.744). GO/KEGG (Gene Ontology/ Kyoto Encyclopedia of Genes and Genomes) analysis, GSVA and single-cell sequencing analysis showed that HOPX expression is associated with immune processes and high enrichment of T cells and could serve as an immune checkpoint in SKCM. Furthermore, cellular assays verified that HOPX inhibits the proliferation, migration and invasion of A375 cells and promotes apoptosis and S-phase arrest. Interestingly, tumor drug sensitivity analysis revealed that HOPX also plays an important role in reducing clinical drug resistance.

CONCLUSION

These findings suggest that HOPX is a blocker of SKCM progression that inhibits the proliferation of SKCM cells and promotes apoptosis. Furthermore, it may be a new diagnostic and prognostic indicator and a novel target for immunotherapy in SKCM patients.

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.

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.

Aetiology and Pathogenesis of Cutaneous Melanoma: Current Concepts and Advances

Melanoma develops from malignant transformations of the pigment-producing melanocytes. If located in the basal layer of the skin epidermis, melanoma is referred to as cutaneous, which is more frequent. However, as melanocytes are be found in the eyes, ears, gastrointestinal tract, genitalia, urinary system, and meninges, cases of mucosal melanoma or other types (e.g., ocular) may occur. The incidence and morbidity of cutaneous melanoma (cM) are constantly increasing worldwide. Australia and New Zealand are world leaders in this regard with a morbidity rate of 54/100,000 and a mortality rate of 5.6/100,000 for 2015. The aim of this review is to consolidate and present the data related to the aetiology and pathogenesis of cutaneous melanoma, thus rendering them easier to understand. In this article we will discuss these problems and the possible impacts on treatment for this disease.