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

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 3 months. Serum gastrin level was elevated to 542 pg/mL (normal: < 100 pg/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 2 cm 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 30 pg/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.