Hunza Chaudhry, MD1, VIctoria Green, MD2, Simarjeet Lamba, MD2, Justin Lewis, MD2, Helen Wong, MD2 1UCSF-Fresno, Fresno, CA; 2UCSF Fresno, Fresno, CA
Introduction: Primary gastric melanoma is a rare malignancy described in isolated case reports. Balloon cell differentiation is a unique histopathological subtype, representing less than 1% of malignant melanoma. We report a case of primary gastric balloon cell melanoma presenting as gastrointestinal (GI) bleed.
Case Description/Methods: A 73-year-old man presented with two days of hematochezia and melena. His physical examination was unremarkable with no suspicious skin lesions. He previously presented with similar symptoms and was found to have gastritis on esophagogastroduodenoscopy (EGD). A computerized tomography (CT) scan of the chest and abdomen, during this admission, revealed distal gastric body wall thickening, a 0.7 cm adjacent soft tissue nodularity, right lung nodule and enlarged hilar lymph node. Repeat EGD revealed multiple submucosal ulcerated, necrotic masses in the stomach (Figure 1a-b), increased in size from the previous EGD two months ago, suggesting an aggressive process. Gastric biopsy revealed balloon-like submucosal epithelioid neoplasm with necrosis and intracytoplasmic pigment concerning for melanoma (Figure 1c). Immunohistochemical testing was positive for Melan-A, SOX10, and S100 consistent with melanoma with balloon cell differentiation. The patient was referred to oncology and underwent a PET scan which confirmed intense uptake in the stomach, hypermetabolic pulmonary nodules, and no skin lesions. A CT-guided biopsy of the pulmonary nodules was negative for malignancy, further confirming primary gastric melanoma. The patient remains under close monitoring with plan for initiation of pembrolizumab.
Discussion: Melanoma is an aggressive malignancy that has a predilection for metastasis to the GI tract. However, primary gastric melanoma is a rare entity and balloon cell is one of the rarest histopathological subtypes. Due to paucity of cases, treatment guidelines are limited. While immune checkpoint inhibitors (ICI) have revolutionized gastric cancer treatment, the use of ICI is understudied in primary gastric melanoma. Further studies investigating the molecular basis of melanoma are needed for development of targeted treatments. Our case emphasizes that symptoms of GI bleeding should be evaluated diligently, as early recognition of malignancy can lead to a prompt diagnosis and initiation of life-saving treatment.
Figure: Figure 1: A-B. EGD showing multiple submucosal ulcerated and necrotic masses in the stomach. C. H&E image showing lamina propria replaced by infiltrating enlarged, voluminous balloon-like cells with oval nuclei, prominent cherry nucleoli, and intracytoplasmic pigment.
Disclosures:
Hunza Chaudhry indicated no relevant financial relationships.
VIctoria Green indicated no relevant financial relationships.
Simarjeet Lamba indicated no relevant financial relationships.
Justin Lewis indicated no relevant financial relationships.
Helen Wong indicated no relevant financial relationships.
Hunza Chaudhry, MD1, VIctoria Green, MD2, Simarjeet Lamba, MD2, Justin Lewis, MD2, Helen Wong, MD2. C0706 - Double Trouble: A Case of Primary Gastric Balloon Cell Melanoma, ACG 2022 Annual Scientific Meeting Abstracts. Charlotte, NC: American College of Gastroenterology.
