Synchronous Gastric Signet-Ring Cell Adenocarcinoma and Mucosa-Associated Lymphoid Tissue (MALT) Lymphoma Treated...

The synchronous occurrence of gastric adenocarcinoma and mucosa-associated lymphoid tissue (MALT) lymphoma is rare, and coexistence with signet-ring cell adenocarcinoma is particularly uncommon. We report a 43-year-old White Brazilian man with a history of gastroesophageal reflux disease, nondysplastic Barrett's esophagus, and previous laparoscopic Nissen fundoplication. During endoscopic follow-up, chronic gastritis, persistent Helicobacter pylori (H. pylori) infection, and gastric MALT lymphoma were identified. Despite eradication therapy, H. pylori and the lymphomatous infiltrate persisted, and a 15-mm depressed antral lesion became evident. Serial biopsies and immunohistochemistry demonstrated synchronous signet-ring cell adenocarcinoma and MALT lymphoma. Endoscopic ultrasonography suggested focal superficial submucosal involvement, whereas computed tomography and positron emission tomography-computed tomography showed no metastatic disease. Following multidisciplinary review, the patient underwent robotic total gastrectomy with D2 lymphadenectomy and Roux-en-Y reconstruction using the da Vinci X platform. The postoperative course was uneventful, and discharge occurred on postoperative day 7. Surgical pathology revealed a 1.2-cm poorly differentiated signet-ring cell adenocarcinoma confined to the muscularis mucosae, residual MALT lymphoma, persistent H. pylori, and no metastatic tumor in 19 lymph nodes (pT1aN0M0). This case emphasizes the need for systematic endoscopic mapping and comprehensive histopathological assessment in gastric MALT lymphoma. In a surgically altered upper abdomen with dense adhesions and potential compromise of remnant fundic perfusion, robotic total gastrectomy provided a feasible minimally invasive strategy for treating both neoplasms.