S2766 Sunburn of the Upper GI Tract: A Case of Metastatic Melanoma of the Stomach and Duodenum

Abstract

INTRODUCTION: Malignant Melanoma is the fifth most common cancer among the population, and it is known to spread to most organs in the body. Severity of this dastardly disease is predicated based on the stage of the cancer. It is one of the most common cancers that can disseminate to the gastrointestinal tract (GIT). To the best of our knowledge as per literary review, there are fewer than 10 reported case reports discussing cutaneous melanoma with metastasis to both stomach and duodenum simultaneously. This case report aims to add yet another example of this phenomenon to the literature. Here, we present a 49-year old female with biopsy proven melanoma of the back, who presented three years later with nausea and vomiting, and was found to have metastasis to the stomach and duodenum. CASE DESCRIPTION/METHODS: Our patient is a 49-year-old female who presented with chief complaints of intractable nausea and vomiting for eight weeks. She was diagnosed with benign superficial spreading melanoma of the back three years prior. Two years later she had a CT chest suggestive of metastatic disease (stage IV), and she was subsequently started on immunotherapy with nivolumab. Given her persistent nausea and vomiting, an EGD was performed which showed three mucosal polypoid nodules, approximately 5–10 mm with tip ulcerations, in the gastric body and multiple mucosal nodules, approximately 5–10 mm, in the duodenum (Figure 1). Biopsies of these nodules showed S-100 and MART-1 positive metastatic melanoma (Figure 2). Genetic sequencing revealed mutations in the following genes: BRAF V600E, PTEN, PD-L1 28-8. DISCUSSION: This case highlights the severity of melanoma and its negative impact on the GIT. Metastatic melanoma of the GIT is a common postmortem finding, however antemortem diagnosis of this lethal disease is quite rare. The most widely used “melanoma markers” are: S-100, HMB-45, and MART-1/Melan-A [6]. It is also important to appreciate that due to their wide differences in sensitivity and specificity, these markers are often tested together to optimize statistical yield. It has been shown that the incidence of metastatic melanoma of the GIT is as follows: Jejunum and ileum 58%, stomach 26%, colon 22%, duodenum 12%, and the least common being to the rectum and anus. GI symptoms in a melanoma patient should always prompt one to explore further endoscopic investigation. In the event of a negative endoscopy in a melanoma patient, one should consider a capsule endoscopy to ensure complete examination of the GIT.Figure 1a.: Mucosal nodules seen in duodenum.Figure 1b.: Mucosal nodule seen in gastric body.Figure 2.: Gastric nodule seen at 100x, stained MART-1 positive (brown). Metastatic infiltration of glands seen (yellow arrows).