Primary malignant melanoma of the esophagogastric junction: A case report

Malignant melanoma of gastrointestinal tract on 18F-FDG PET/CT: three case reports

Primary malignant melanoma most frequently occurs in the skin. Melanoma affecting the gastrointestinal (GI) tract has been substantiated for lesions occurring in the esophagus, stomach, small bowel, and anorectum through multiple published reports, given the presence of melanocytes in these areas. Nevertheless, owing to the exceedingly low incidence of this disease, reports on its clinical features are few, and treatment approaches lack standardization. In this study, we present three cases of GI melanoma with imaging manifestations, emphasizing the pivotal role of 18F-FDG PET/CT in staging for GI melanoma. Establishing a definitive diagnosis of primary GI melanoma necessitates the exclusion of the possibility of metastasis from more prevalent primary sites. Advancements in molecular imaging technologies and the development of novel tracers provided significant promising methods for enhancing the diagnosis and management of melanoma, contributing to improved patient outcomes and overall disease management.

Interaction between Age and Primary Site on Survival Outcomes in Primary GI Melanoma over the Past Decade

BACKGROUND

Primary malignant melanomas of the Gastrointestinal mucosa are uncommon. Most cases of gastrointestinal (GI) melanomas are secondary, arising from metastasis at distant sites. The purpose of this study is to assess to what extent the interaction between independent prognostic factors (age and tumor site) of primary GI melanoma influence survival. Furthermore, we also aimed to investigate the clinical characteristics, survival outcomes, and independent prognostic factors of patients with primary GI melanoma in the past decade.

METHODS

A total of 399 patients diagnosed with primary GI melanoma, between 2008 and 2017, were enrolled in our study by retrieving data from the Surveillance, Epidemiology, and End Results (SEER) database. We analyzed demographics, clinical characteristics, and overall mortality (OM) as well as cancer-specific mortality (CSM) of primary GI melanoma. Variables with a p value < 0.1 in the univariate Cox regression were incorporated into the multivariate Cox model (model 1) to determine the independent prognostic factors, with a hazard ratio (HR) of greater than 1 representing adverse prognostic factors. Furthermore, we analyzed the effect of the interaction between age and primary location on mortality (model 2).

RESULTS

Multivariate cox proportional hazard regression analyses revealed higher OM in age group 80+ (HR = 5.653, 95% CI 2.212-14.445, p = 0), stomach location of the tumor (HR = 2.821, 95% CI 1.265-6.292, p = 0.011), regional lymph node involvement only (HR = 1.664, 95% CI 1.051-2.635, p < 0.05), regional involvement by both direct extension and lymph node involvement (HR = 1.755, 95% CI 1.047-2.943, p < 0.05) and distant metastases (HR = 4.491, 95% CI 3.115-6.476, p = 0), whereas the lowest OM was observed in patients with small intestine melanoma (HR = 0.383, 95% CI 0.173-0.846, p < 0.05). Multivariate cox proportional hazard regression analyses of CSM also revealed higher mortality of the same groups and lower CSM in small intestine and colon melanoma excluding the rectum. For model 2, considering the interaction between age and primary site on mortality, higher OM was found in age group 80+, followed by age group 40-59 then age group 60-79, regional lymph node involvement only, regional involvement by both direct extension and lymph node involvement and distant metastases. The small intestine had a lower OM. The rectum as primary location and the age range 40-59 interacted to lower the OM (HR = 0.14, 95% CI 0.02-0.89, p = 0.038). Age and primary gastric location did not interact to affect the OM. For the CSM, taking into account the interaction between age and the primary location, higher mortality was found in the same groups and the colon location. The primary colon location also interacted with the age group 40-59 to increase the CSM (HR = 1.38 × 10⁹, 95% CI 7.80 × 10⁷-2.45 × 10¹⁰, p = 0).

CONCLUSIONS

In this United States population-based retrospective cohort study using the SEER database, we found that only the age range 40-59 interacted with the rectum and colon to lower and increase mortality respectively. Primary gastric location, which was the single most important location to affect mortality, did not interact with any age range to influence mortality. With those results, we hope to shed some light on this rare pathology with a very dismal prognosis.

The Thousand Faces of Malignant Melanoma: A Systematic Review of the Primary Malignant Melanoma of the Esophagus

Primary Malignant Melanoma of the Esophagus (PMME) is an extremely rare cancer of the esophagus, accounting for 0.1−0.8% of all oro-esophageal cancers and <0.05% of all melanoma subtypes, with an estimated incidence of 0.0036 cases per million/year. We conduct a careful analysis of the literature starting from 1906 to the beginning of 2022, searching the PubMed, Science.gov, Scopus and Web of Science (WoS) databases. A total of 457 records were initially identified in the literature search, of which 17 were duplicates. After screening for eligibility and inclusion criteria, 303 publications were ultimately included, related to 347 patients with PMME. PMME represents a very rare entity whose very existence has been the subject of debate for a long time. Over time, an increasing number of cases have been reported in the literature, leading to an increase in knowledge and laying the foundations for a discussion on the treatment of this pathology, which still remains largely represented by surgery. In recent times, the possibility of discovering greater mutations in gene hotspots has made it possible to develop new therapeutic strategies of which nivolumab is an example. Future studies with large case series, with clinicopathological and molecular data, will be necessary to improve the outcome of patients with PMME.

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.