P2069 - Rare Case of Gastric Small Cell Carcinoma

Jonathan Vincent M. Reyes, MD, MHA¹, Nagma Shah, MD¹, Fahad Malik, MD², Omar Al Salman, MD^3
1Icahn School of Medicine at Mount Sinai (Elmhurst Hospital Center), Elmhurst, NY; ²UHS Wilson Hospital, Johnson City, NY; ³Metropolitan Hospital Center, New York, NY

Introduction: Gastric cancer remains one of the most common cancers worldwide. The majority of cases are adenocarcinomas and < 0.1% of cases are small cell carcinoma. Small cell carcinoma of the stomach is extremely rare, highly malignant, and carries a poor prognosis.

Case Description/Methods: A 53-year-old male presented with 8-month history of generalized abdominal pain associated with nausea, 60-pound weight loss, and decreased appetite. Past medical history was significant for HTN. Labs were within normal limits. He endorsed a smoking history of 0.5 packs per day over 30 years as well as daily alcohol use. CT Chest with IV contrast was unrevealing. His symptoms and presentation were further evaluated with an esophagogastroduodenoscopy which revealed a large ulcerated mass without signs of active bleeding in the gastric fundus and body. This mass is continuous at the gastroesophageal junction, 42cm from the incisors. Esophageal and gastric tumors were biopsied and revealed positive CK CAM 5.2, CKAE1/3, CK7, CDX-2, synaptophysin, TTF-1, Ki-67, PAX-5, and negative for CK20, cyclin D1, CD5, CD3, and CD20. Immunohistochemistry supports the diagnosis of primary small cell carcinoma.

Discussion: Small cell carcinomas originate from totipotent cells present in all tissues. Extrapulmonary SCC comprises just 2.5% of all cases. 11% of SCC cases found within the GIT were of gastric origin. Risk factors include H. pylori, diet, obesity, smoking, alcohol, nitrates with incidence rates highest in Eastern Asia. Reported cases of GSCC have presented with epigastric tenderness, unintentional weight loss, jaundice, lethargy, and abdominal distention. Diagnosis involves endoscopy followed by histology which characteristically demonstrates small, oval lymphocyte-like cells with hyperchromatic nuclei and scant cytoplasm and immunohistochemistry positive for CD56, Ki-67, cytokeratin, synaptophysin, and chromogranin. The survival rate ranges between 1.5 months and 11 years depending on the extent of the disease. The same chemotherapies for pulmonary SCC, cisplatin, and etoposide, have shown increased survival rates in GSCC patients. Two clinical trials, REGARD, and RAINBOW indicate second-line treatment ramucirumab (VEGF inhibitor) as monotherapy and in combination with paclitaxel has a statistically significant benefit and is FDA approved. These trials serve as a stepping stone for future treatment options for GSCC.



Disclosures:


Jonathan Vincent M. Reyes, MD, MHA¹, Nagma Shah, MD¹, Fahad Malik, MD², Omar Al Salman, MD³. P2069 - Rare Case of Gastric Small Cell Carcinoma, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.