S6323 Gastric Small Cell Carcinoma Presenting as a Fungating Mass in the Gastric Cardia: A Rare Case Report

Introduction: Gastric small cell carcinoma (GSCC) is an exceedingly rare and aggressive neuroendocrine malignancy. It constitutes less than 0.1% of gastric cancers. GSCC, mostly presenting as an ulcerative lesion, is typically seen in Japanese in their 70s. Here, we report an unusual case of fungating GSCC lesion in an African American patient in his 60s. It emphasizes the need for vigilance in diagnosing atypical gastric cancers. Case Description/Methods: A 63-year-old African American man with a history of prostate adenocarcinoma (status post-prostatectomy) and a 30-pack-year history of smoking presented with heartburn and dyspepsia, which were attributed to gastroesophageal reflux disease (GERD). Initial esophagogastroduodenoscopy (EGD) revealed only erythematous gastric mucosa. H. pylori was negative. Proton pump inhibitors were prescribed which improved symptoms. However, 2 years later, patient was evaluated for similar symptoms and a repeat EGD was done which again showed erythematous gastric mucosa with negative H. pylori, and an increased dose of PPIs was recommended. Three years later, patient presented to the hospital with fatigue and severe anemia (hemoglobin 4.7 mg/dL). A repeat EGD revealed a fungating mass in the gastric cardia. Biopsy confirmed primary GSCC, with immunohistochemistry positive for CK8/18, TTF-1, synaptophysin, and focal chromogranin staining. Imaging excluded metastasis. The patient was started on carboplatin and etoposide-based chemotherapy. Discussion: GSCC is known for its aggressive progression and poor prognosis, with early lymphatic spread being common. Most of the cases present as ulcerative lesions while the fungating manifestation is extremely rare. A review of 9 GSCC cases highlighted epigastric pain and anemia as frequent presentations. Histopathology consistently shows neuroendocrine markers, with chemotherapy, often platinum-based, being the mainstay of treatment. Our case is unique in its rapid progression from benign-appearing gastritis to carcinoma within a short time frame. Furthermore, it is the first reported case of fungating GSCC in an African-American patient. There is a need of future studies to characterize the appropriate follow up interval in such cases for early diagnosis and prompt treatment.