The challenge of primary gastric melanoma: a systematic review

Melanoma - goes where it wants and does what it pleases. A case report of primary gastric melanoma

Melanoma is a common global cancer, however, extracutaneous forms are most often from metastasis. Primary extracutaneous forms are rare, with primary gastric melanoma exceedingly so, with approximately only 50 cases reported worldwide in the literature. The mainstay of management is surgical resection with minimal data on adjuvant therapy. Its prognosis remains poor due to its aggressive behaviour and late presentation. Our case demonstrates a primary gastric melanoma presenting with gastric perforation requiring emergency operative management.

The evidence for Mycobacterium avium subspecies paratuberculosis (MAP) as a cause of nonsolar uveal melanoma: a narrative review

Background and Objective

Animal microorganisms have been proposed as a cause of human cancers associated with farming, agricultural occupation or residence, and related downstream exposures. Several studies have described uveal melanoma (UvM) as a farming-associated cancer. A possible suspect is the animal microorganism Mycobacterium avium subspecies paratuberculosis (MAP), the causative agent of paratuberculosis in dairy cows. This microbe is transmitted to humans through various means, including contact with animal faeces, contaminated dust and soil, organic fertilizers, and as workers in slaughterhouses/animal processing facilities. The objective of the current manuscript was to examine the putative association between Mycobacterium avium sub-species paratuberculosis and non-solar UvM.

Methods

Online data sources (PubMed, Scopus, Cochrane Library, and Google) published in English between 1980 to present were searched for key words pertaining to MAP exposure, farming-related occupations and activities, and locations with or in the vicinity of dairy cattle.

Key Content and Findings

While higher than expected rates of eye cancer have been suggested among dairy farmers, with MAP being ubiquitous in their environment, the involvement of MAP in the aetiology of non-solar UvMs (which account for ~97% of UvM cases) remains uncertain.

Conclusions

Alternative explanations exist and future cause-and-effect research is needed to answer this hypothesis. A precautionary approach to exposure continues to be a prudent strategy.

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.

Malignant melanoma in the stomach treated with endoscopic submucosal dissection: a case report

The initial appearance of malignant melanoma localized in the stomach has never been reported previously. We encountered a patient with gastric melanoma in the stomach, which was histologically confirmed to be confined to the mucosa.

Case Presentation

The patient, when in her 40s, had undergone surgery for malignant melanoma of the left heel. However, there were no detailed records of pathological findings. The patient had a 4-mm black elevated lesion in her stomach observed on esophagogastroduodenoscopy after the eradication of Helicobacter pylori. A year later, esophagogastroduodenoscopy showed that the lesion had increased to 8 mm. A biopsy was performed, but no malignancy was found; the patient continued to be followed up. Esophagogastroduodenoscopy performed at the 2-year follow-up revealed that the melanotic lesion had increased to 15 mm, and biopsy was performed and revealed a malignant melanoma.

Clinical Discussion

Endoscopic submucosal dissection was performed for gastric malignant melanoma. The margin of the resected malignant melanoma was negative; vascular and lymphatic invasions were not observed, and the lesion was confined to the mucosa.

Conclusion

We suggest that even if the first biopsy of a melanotic lesion shows no evidence of malignancy, the lesion should be closely monitored. This is the first reported case of endoscopic submucosal dissection of localized gastric malignant melanoma confined to the mucosa.

Wandering Mucosal Melanoma Presenting as Occult Gastrointestinal Blood Loss Anemia

Malignant melanoma is a highly aggressive cancer arising from the skin, retina, and mucosal lining of the respiratory, gastrointestinal (GI), or genitourinary tracts, all of which contain melanocytes. Mucosal or extracutaneous melanomas (ECMs) are rare accounting for 1% of all melanomas. We herein report a case of a metastatic mucosal melanoma presenting as occult blood loss anemia.

A 58-year-old male presented with generalized weakness, anorexia, weight loss, and intermittent melena for one year. On exam, he was tachycardic, borderline hypotensive, and pale without epigastric tenderness. Labs showed severe anemia [hemoglobin, Hgb 3.8 mg/dL, mean corpuscular volume (MCV) 72 fl] for which he received two units of red cells. Endoscopy revealed an 8 mm non-bleeding, gastric ulcer with a raised border and a clean base on the wall of the gastric body. Histologic analysis was consistent with malignant melanoma displaying strong positivity for S-100, Melan A, and HMB 45 stains. The CT of the abdomen revealed multifocal metastatic disease with subcutaneous, intramuscular, and perinephric implants with suspicion of small bowel carcinomatosis. The patient underwent an excisional biopsy for the abdominal wall mass and surgical pathology confirmed melanoma. The patient is planned to be started on immunotherapy for advanced disease.

Most melanomas found in the GI tract are metastatic. Mucosal melanoma presenting as a gastric ulcer is extremely rare. As a result, metastasis from other sites must be ruled out before making a diagnosis of primary gastric melanoma (PGM). In our case, a widespread disease with unknown primary elucidated the diagnosis but post-operative inspection failed to find any potential lesion on the skin, genitals, or other organs, suggesting the possible diagnosis of metastatic gastric melanoma. However, follow-up is still required to confirm the diagnosis according to the established criteria. Pathologic diagnosis of melanoma requires the identification of melanin in the cytoplasm and immunohistochemistry with specific markers such as S-100, Melan A, and HMB-45. Although the pathologic diagnosis of PGM is similar to cutaneous melanoma, preoperative diagnosis is difficult due to the extremely low incidence, lack of obvious melanin pigmentation, similar microscopic patterns as more common gastric cancers, and lack of awareness among physicians and pathologists.

The prognosis of mucosal melanoma is poor, with a five-year survival rate of 25% versus 80% for cutaneous melanoma. Advanced age, surgically unresectable disease, and lymph node involvement are all poor prognostic markers. There is no standard protocol for treatment. Surgery is the only curative treatment for the resectable disease. Adjuvant chemotherapy, radiation, and immunotherapy have an established role in cutaneous melanoma but there is only limited data on adjuvant systemic therapy with mucosal melanoma. Further research is imperative to establish proper management guidelines for this rare disease entity.

Primary Gastric Malignant Melanoma in a 68-Year-Old Woman: A Case Report and Review of the Literature

Non-cutaneous melanoma is a very rare clinical entity. Gastric melanoma can be primary or secondary, but determining their nature is in most cases very challenging. To date, very few cases of primary gastric melanoma have been described in the literature. We report the first case of primary gastric melanoma documented in a Romanian patient, confirmed through clinical, imagistic, and pathological diagnosis. A 68-year-old female patient presented to our hospital with complaints of dyspepsia, abdominal pain, and weight loss. Esophagogastroduodenoscopy revealed two large sessile masses in the gastric fundus, which was histologically compatible with melanoma; immunohistochemistry staining was positive for vimentin, S100 protein, HMB45 antibody and Melan A/MART1, and negative for pan-CKAE1/AE3, leukocyte common antigen and DOG1. Extensive dermatological and ophthalmological examinations did not identify a primary lesion. The patient was therefore diagnosed with primary melanoma of the stomach. At the time of the diagnosis, multiple bone and pulmonary metastases were detected and considering the poor general status of the patient, surgery was not recommended. She died three months following diagnosis. A review of the literature identified only 32 other reported cases of primary gastric melanoma, all in individuals ≥50 years of age and most of them in male patients. Partial or total gastrectomy was the usual treatment of choice, but prognosis was overall poor. Awareness of this rare condition must be increased among healthcare providers, as early detection can improve survival chances.

A case of primary malignant melanoma of the esophagogastric junction with abscopal effect after nivolumab administration

BACKGROUND

The abscopal effect is a rare phenomenon in which local irradiation causes tumor regression outside the irradiated area. There have been no reports of abscopal effect in patients with gastrointestinal melanoma with metastasis. Here, we report a case of primary malignant melanoma of the esophagogastric junction with abscopal effect after long-term treatment with nivolumab.

CASE PRESENTATION

A 75-year-old woman was referred to our hospital with a gastroesophageal lesion. Upper gastrointestinal endoscopy revealed a raised lesion on the posterior wall of the greater curvature of the cardia and tenderness in the lower esophagus. Immunostaining of the tumor biopsy showed positive staining for Melan-A, human melanoma black-45 (HMB45), and S-100, indicating malignant melanoma of the esophagogastric junction. Contrast-enhanced computed tomography (CT) of the abdomen showed a mildly stained lesion protruding into the cardiac part of stomach and enlarged surrounding lymph nodes. The patient was diagnosed with malignant melanoma of the esophagogastric junction and proximal gastrectomy with lower esophagus resection was performed. Histological examination showed large, round tumor cells with nuclear atypia. Immunostaining was positive for Melan A, HMB45, S-100 protein, and SRY-box transcription factor 10, and the final diagnosis was malignant melanoma of the esophagogastric junction, with regional lymph node metastases. Three months after surgery, follow-up CT indicated left pleural metastasis; therefore, the patient was administered nivolumab, an immune checkpoint inhibitor (ICI). Following three courses of nivolumab, the patient exhibited grade 3 renal dysfunction (Common Terminology Criteria for Adverse Events version 5.0). After that, we have not administered nivolumab treatment. Five months after the development of renal dysfunction, a CT scan demonstrated an unstained nodule within the pancreatic, and the patient was diagnosed with pancreatic metastasis; intensity-modulated radiotherapy was performed. Six months later, CT revealed pancreatic nodule and pleural metastasis was shrunk; after an additional 2 months, pleural metastasis and effusion had disappeared. The patient is alive with no additional lesions.

CONCLUSIONS

We report a case of primary malignant melanoma of the esophagogastric junction with an abscopal effect following nivolumab treatment. The findings of this case report suggest that ICIs in combination with radiotherapy may be effective for treating metastatic or recurrent malignant melanoma of the gastrointestinal tract.

Primary malignant melanoma of the gastric antrum: A case report

Primary melanoma of the antrum is a rare and aggressive disease. Diagnosis requires a correlation between the patient's history, tumor histopathology, and immunohistochemistry. Surgery and mutation-targeted treatments may improve overall survival.