Coexistence of Gastrointestinal Stromal Tumor of the Stomach and Small Bowel Adenocarcinoma: A Case Report

Abstract

The coexistence of gastrointestinal tumors (GIST's) with other several primary malignant neoplasms has been demonstrated. However, there is no study that reported simultaneous occurrence of primary small bowel adenocarcinoma (SBA) and a GIST located in the stomach. Here, we report the first case of SBA and a synchronous gastric GIST. Surgical resection and clinicopathological characterization were performed for the masses identified through endoscopic and radiologic studies. Computed tomography scan showed a 13 mm mass located at the gastric antrum and another mass lesion partially occluding the jejunum. A biopsy specimen was obtained from the mass at the proximal jejunum by enteroscopy. The tumor was reported as adenocarcinoma. The patient was operated by the general surgery team. The features of the submucosal lesion resected from the antrum were consistent with a diagnosis of a GIST which contained spindle cells and showed positive staining with CD-117 and CD-34. Mitosis was not observed, and Ki 67 index was below 10%. This is the first case of coexistence of GIST of the stomach and SBA to be reported in English-language literature. The prominent characteristics of our case include its antral localization, male sex, absence of mitosis and incidental diagnosis. © 2021 Ondokuz Mayis Universitesi. All rights reserved.