Russell body gastritis: a clinicopathological analysis of five cases and literature review.

Russell body gastritis (RBG) is a rare chronic gastritis characterized by infiltration of plasma cells (Mott cells) rich in Russell bodies in the gastric mucosa. This study aims to systematically expound the clinicopathological and immunohistochemical characteristics of RBG through case analysis and literature review. A retrospective analysis was conducted on 5cases of RBG diagnosed in Guizhou Moutai Hospital, Jinhu County People's Hospital, and Zigong First People's Hospital from December 2018 to December 2023. We collected clinical, endoscopic, pathological, and follow-up data from these patients. At the same time, we reviewed the relevant literature. Among the 5 patients in this group, 3 were female and 2 were male, with a median age of 55 years (ranging from 53 to 67 years). Four cases (80%) had lesions located in the antrum of the stomach, and one case (20%) was located in the cardia. One case (20%) was accompanied by Helicobacter pylori (HP) infection. Histologically, a large number of Mott cells were observed. Immunohistochemistry showed positive CD38, CD138, and MUM-1, negative cytokeratin (CK), co-expression of κ and λ light chains (polyclonal), and positive PAS staining. One HP-positive patient received eradication treatment, and four HP-negative patients received proton pump inhibitor (PPI) treatment. During the follow-up period, the conditions of all patients were stable without progression. RBG is a benign lesion with characteristic histological manifestations. Its diagnosis depends on histological manifestations and immunohistochemistry.