Mucosal melanomas: Site-specific information, comparisons with cutaneous tumors, and differential diagnosis

[Anorectal melanoma : Update on clinical presentation, diagnosis and treatment]

Anorectal melanomas are a rare malignant type of cancer and pose a diagnostic challenge due to their hidden anatomical location. They are associated with nonspecific clinical symptoms and are therefore often misinterpreted as benign disease. The result is delayed diagnosis in the locally advanced or metastasized stage and an unfavorable prognosis. Given the overall low incidence of the tumor, no consensus guidelines for diagnosis or therapy are established either internationally or nationally at present. The present work intends to provide a comprehensive overview of the clinical aspects, diagnostics, and therapeutic approaches of anorectal melanoma based on the currently available literature.

Connecting the dots: Melanoma cell of origin, tumor cell plasticity, trans-differentiation, and drug resistance

Melanoma, a lethal malignancy that arises from melanocytes, exhibits a multiplicity of clinico-pathologically distinct subtypes in sun-exposed and non-sun-exposed areas. Melanocytes are derived from multipotent neural crest cells and are present in diverse anatomical locations, including skin, eyes, and various mucosal membranes. Tissue-resident melanocyte stem cells and melanocyte precursors contribute to melanocyte renewal. Elegant studies using mouse genetic models have shown that melanoma can arise from either melanocyte stem cells or differentiated pigment-producing melanocytes depending on a combination of tissue and anatomical site of origin and activation of oncogenic mutations (or overexpression) and/or the repression in expression or inactivating mutations in tumor suppressors. This variation raises the possibility that different subtypes of human melanomas (even subsets within each subtype) may also be a manifestation of malignancies of distinct cells of origin. Melanoma is known to exhibit phenotypic plasticity and trans-differentiation (defined as a tendency to differentiate into cell lineages other than the original lineage from which the tumor arose) along vascular and neural lineages. Additionally, stem cell-like properties such as pseudo-epithelial-to-mesenchymal (EMT-like) transition and expression of stem cell-related genes have also been associated with the development of melanoma drug resistance. Recent studies that employed reprogramming melanoma cells to induced pluripotent stem cells have uncovered potential relationships between melanoma plasticity, trans-differentiation, and drug resistance and implications for cell or origin of human cutaneous melanoma. This review provides a comprehensive summary of the current state of knowledge on melanoma cell of origin and the relationship between tumor cell plasticity and drug resistance.

An Unusual Case of Primary Gastric Balloon Cell Melanoma

Most cases of melanoma found in the gastrointestinal tract are the result of metastasis. Although uncommon and only described in isolated case reports, primary gastric melanoma should be considered when patients present with vague gastrointestinal symptoms and a mass is identified on esophagogastroduodenoscopy or imaging. We describe a case of primary gastric balloon cell melanoma in a 73-year-old man who presented with melena. Given the high morbidity and mortality of gastric mucosal melanoma, early diagnosis and initiation of treatment can lead to improved outcomes and survival.

Prognostic and immune-related value of complement C1Q (C1QA, C1QB, and C1QC) in skin cutaneous melanoma

Background: Skin cutaneous melanoma (SKCM) is a common malignancy that is associated with increased morbidity and mortality. Complement C1Q is composed of C1QA, C1QB, and C1QC and is involved in the occurrence and development of many malignant tumours. However, the effect of C1QA, C1QB, and C1QC expression on tumour immunity and prognosis of cutaneous melanoma remains unclear.

Methods: First, we analysed C1QA, C1QB, and C1QC expression levels and prognostic values using Gene Expression Profiling Interactive Analysis (GEPIA) and Tumour Immune Estimation Resource (TIMER) analysis, and further validation was performed using RT-qPCR, The Human Protein Atlas, The Cancer Genome Atlas (TCGA) dataset, and Gene Expression Omnibus dataset. We then performed univariate/multivariate Cox proportional hazard model, clinicopathological correlation, and receiver operating characteristic curve analysis using TCGA dataset and established a nomogram model. Differentially expressed genes associated with C1QA, C1QB, and C1QC in SKCM were identified and analysed using LinkedOmics, TIMER, the Search Tool for the Retrieval of Interacting Genes database, and Metascape and Cytoscape software platforms. We used TIMER, GEPIA, and single-sample gene set enrichment analysis (ssGSEA) to analyse the relationship between the three genes and the level of immune cell infiltration, biomarkers, and checkpoint expression in SKCM. Finally, GSEA was utilized to study the functional pathways of C1QA, C1QB, and C1QC enrichment in SKCM.

Results: The overexpression of C1QA, C1QB, and C1QC provided significant value in the diagnosis of SKCM and has been associated with better overall survival (OS). Multivariate Cox regression analysis indicated that C1QA, C1QB, and C1QC are independent prognostic biomarkers for patients with SKCM. Immune cell infiltration, biomarkers, and checkpoints were positively correlated with the expression of C1QA, C1QB, and C1QC. Furthermore, the results of functional and pathway enrichment analysis showed that immune-related and apoptotic pathways were significantly enriched in the high-expression group of C1QA, C1QB, and C1QC.

Conclusion: We found that C1QA, C1QB, and C1QC can be used as biomarkers for the diagnosis and prognosis of SKCM patients. The upregulated expression levels of these three complement components benefit patients from OS and may increase the effect of immunotherapy. This result may be due to the dual effects of anti-tumour immunity and apoptosis.

Vulvar and vaginal melanomas: A retrospective study spanning 19 years from a tertiary center

INTRODUCTION

Mucosal melanomas (MM) of the female genital tract are rare a. We aimed to study the prognostic factors of vulvar and vaginal locations of MM.

MATERIAL AND METHOD

A multicenter, retrospective cohort study conducted between 01/01/2000 and 01/06/2019.

RESULT

Of the 33 patients included 25 (75.8 %) had vulvar (VuM) and eight (24.2 %) vaginal melanomas (VaM). VaMs were deeper: median Breslow index: 17.5mm [3.5-22] versus 4.3mm [0.35-18] (p=0.013). Average follow-up was 24.0±59.8 months. Twenty-six patients (78.8 %) experienced recurrence. Disease-free survival was 52.9 % at 1year (64.7 % for VuM and 14.3 % for VaM) and 8.4 % at 3 years (11 % for VuM and 0% for VaM) (p=0.002). Median time to the first recurrence was 9.01 months [CI95 %: 2.07-56.71]. VaM recurred earlier than VuM (3.12 months [CI95 %: 2.07-12.49] versus 17.72 [CI95 %: 3.58-56.71], p=0.011). VaM had a higher risk of recurrence (HR=5.64 [CI95 %: 2.01-15.82], p=0.001) in multivariate analysis. Overall survival was 88.5 % at 1year (100 % for VuM and 50 % for VaM), and 59.4 % at 3 years (69.3 % for VuM and 25 % for VaM). Women with VaM died earlier: median specific death occurrence of 8.76 months [CI95 %: 6.54-24.72] versus 39.61 [CI95 %: 21.89-209.21], p=0.013 (HR=5.08 [CI95 %: 1.39-18.60], p=0.014). A lesion size ≥3cm was associated with an increased risk of mortality (HR=8.45 [CI95 %: 1.60-44.52], p=0.012). In multivariate analysis, vaginal location remained an independent and predictive variable of a higher risk of specific death (HR=8.56 [CI95 %: 1.95-37.64], p=0.005).

CONCLUSION

A vaginal location of MM is associated with a poorer prognosis than a vulvar location.

Primary Gastric Malignant Melanoma

Primary gastric malignant melanoma (PGMM) is an extremely rare clinical entity, and few cases have been described in the literature. Here, we report a histologically confirmed PGMM case of a 74-year-old man with a mass in the stomach found by gastroscopy. The patient had no history of melanoma. This rare disease may be misdiagnosed for another gastric malignant tumor type when there is no known primary lesion. Early detection and surgical intervention are critical for long term survival or cure, though the tumor is often advanced at the time of diagnosis and is associated with a dismal outcome.

Primary malignant melanoma of the urethra in a patient with rheumatoid arthritis treated with methotrexate

We report a case of a 79-year-old woman with urinary incontinence who presented at a urogynaecology appointment. Her medical history included rheumatoid arthritis (RA) treated with methotrexate (MXT) for 22 years. A polypoidal lesion was protruding from the meatus urethrae. The histoimmunocytology confirmed a primary superficial spreading malignant melanoma. The tumour was extensively excised, but 8 months later, due to a lymphatic nodal swelling, a positron emission tomography/CT was performed showing a process suspicious of malignant melanoma and multiple distant metastasis. The subsequent treatment was palliative and 1 year later, the patient died. The aetiology of malignant melanomas in the urethra is poorly understood. There is consistent evidence that RA is associated with a number of cancers, but it remains controversial whether this risk is increased with MXT. This case emphasises the importance of gynaecological examination even in patients with only weak symptoms from the pelvic region, especially in patients undergoing immunosuppressive treatment.

A Case of Primary Gastric Melanoma Exhibiting a Rare BRAF V600R Mutation

Introduction

Malignant melanoma of the gastrointestinal tract is usually a metastasis from a cutaneous source. Primary gastric melanoma is an extremely rare clinical entity, with few reported cases worldwide. It is often advanced at time of diagnosis and is associated with a dismal outcome.

Background

A 76 year old gentleman presenteded with a one month history of fatigue and exertional dyspnoea. Laboratory investigations indicated an anaemia, with a haemoglobin level of 11.0g/dl. Subsequent gastroscopy visualised a large, atypical, crater-like ulcerated lesion distal to the cardia in the proximal stomach.

Provisional histology was suggestive of a poorly differentiated adenocarcinoma but subsequent cyto-morphology and immunophenotyping were consistent with melanoma, with positive S100 protein, HMB45 and Melan A. Further molecular genetic testing revealed a V600R mutation in the BRAF gene, which is the first primary gastric melanoma with this mutation to be reported in the literature. Given the rarity of the findings, an extensive secondary work-up was undertaken, which concluded the diagnosis primary gastric melanoma.

Discussion

Primary gastric melanoma is a rare disease that can present similarly to other upper gastrointesinal lesions, with weight loss, abdominal pain, malena, and anaemia. Given its rarity, the pathogenesis is poorly understood. Lesions are often endoscopically atypical. Important points to note would include the absence of a primary lesion, as supported by a full skin examination and PET-CT findings, which can help to delineate the limitation to the stomach, thus helping to inform subsequent management.

LEARNING POINTS

Somatic driver mutations in melanoma

Melanoma has one of the highest somatic mutational burdens among solid malignancies. Although the rapid progress in genomic research has contributed immensely to our understanding of the pathogenesis of melanoma, the clinical significance of the vast array of genomic alterations discovered by next-generation sequencing is far from being fully characterized. Most mutations prevalent in melanoma are simply neutral "passengers," which accompany functionally significant "drivers" under transforming conditions. The delineation of driver mutations from passenger mutations is critical to the development of targeted therapies. Novel advances in genomic data analysis have aided in distinguishing true driver mutations involved in tumor progression. Here, the authors review the current literature on important somatic driver mutations in melanoma, along with the implications for treatment. Cancer 2017;123:2104-17. © 2017 American Cancer Society.

Loco-Regional Control With Complete Resection and Tongue Reconstruction on the Malignant Melanoma in the Tongue

Primary malignant melanoma in the tongue is very uncommon disease that is considered low in comparison to cutaneous melanoma. In this report, the authors described a case of the hemitongue reconstruction with fasciocutaneous free flap on the patient who suffered from the malignant melanoma primarily originating from the base of the tongue that was treated with surgery and radiotherapy but developed a lung metastasis. A 76-year-old man was referred to the otorhinolaryngology clinic after complaining of a painful mass present for 3 months on the right side of the tongue. A punch biopsy was revealed atypical cells with pigmentation that is consistent with malignant melanoma. After wide excision and bilateral neck dissection performed, hemipartial tongue reconstruction was done using a radial forearm free flap. The patient had an uneventful recovery and received a course of radiotherapy along with follow-up examinations for 3 years. The authors report this rare patient for providing the other surgeons with the useful information regarding the management of the malignant melanoma on the tongue with free flap reconstruction which turned out to be successful in loco-regional control.