The Occurrence, Development, and Histopathological Staging of Gastric Adenocarcinoma of Fundic Glands

Objective: This study aims to investigate the occurrence, development, and histopathological staging of gastric adenocarcinoma of the fundic glands (GA-FG).Methods: Detailed histological observations, immunohistochemistry staining as well as follow-ups were conducted on specimens from 215 patients with abnormal proliferative lesions of the gastric fundic glands, who had undergone endoscopic biopsies and endoscopic submucosal dissection.Results: Four stages were observed in GA-FG. The first stage was the benign proliferative stage, where the lesions were located in the local proliferative region of the fundic glands, and the lesions could be divided into two types: Ductal proliferation and cystic dilatation. The second stage was the gastric fundic glandular adenoma stage, where the lesions were mainly located in the gastric mucosa layer and could be divided into two types: Gastric fundic microadenoma and gastric fundic adenoma. The third stage was the atypical proliferative stage of the gastric fundic glands, in which the lesion invaded the mucosal muscle, and <= 50% of the mucosal muscle was interspersed with abnormal proliferative glandular ducts. The lesions could be divided into two types: Atypical ductal proliferation of the glands and atypical cystic dilatation of the glands. The fourth stage was the GA-FG stage, in which the lesion directly invaded the mucosal muscle layer as far as the submucosa, and the lesions could be divided into three types: GA-FG with low proliferative activity, GA-FG with high proliferative activity, and cystic GA-FG.Conclusions: These lesions can be divided into the following four types based on the stage of occurrence: Benign hyperplasia of the gastric fundic glands, adenoma of the gastric fundic glands, atypical hyperplasia of the gastric fundic glands, and GA-FG. This staging should enable clinicians to administer targeted treatment and track cellular transformation, which is important for monitoring the development of GA-FG.