Concomitant multifocal gastrinomas and adenocarcinoma in the stomach: A case report and literature review

Abstract

The stomach is an uncommon location for gastrinomas. Here we report a rare case of multifocal gastrinomas in the antrum with concomitant gastric adenocarcinoma and neuroendocrine cell hyperplasia. The patient was a 35-year-old man who presented with mild upper abdominal discomfort for 3months. Serum gastrin level was elevated to 542pg/mL (normal: <100pg/mL). Endoscopic examination revealed multiple polyps in the antrum, which proved to be carcinoid tumors on biopsy. Partial gastrectomy was performed. The surgical specimen contained multiple pedunculated polyps measuring up to 2cm in greatest dimension. Additionally, many small, sessile polyps with central umbilication were identified in the antrum and the pylorus. Histological and immunohistochemical studies of the polyps showed nests of low-grade tumor cells that were positive for gastrin, confirming a diagnosis of multifocal gastrinoma. Incidentally, one large polyp was found to harbor a focus of poorly-differentiated adenocarcinoma with signet ring cell features. Diffuse enterochromaffin-like cell hyperplasia and small carcinoid tumors were identified in the body of the stomach. Regional lymph nodes were positive for both adenocarcinoma and gastrinoma. In addition, Helicobacter pylori-like organisms were detected in the antral mucosa. The post-operative course was uneventful, and the patient's serum gastrin level dropped to 30pg/mL. He is currently receiving chemotherapy for the adenocarcinoma. This is a rare case of multifocal gastrinoma in an unusual location. It has already been established that hypergastrinemia plays a role in the pathogenesis of gastric adenocarcinoma and neuroendocrine neoplasms. Therefore, it is important to rule out these concomitant lesions, both clinically and pathologically, when dealing with a proven gastrinoma.