Comparative Analysis of Gastric Epithelial Neoplasm of Fundic-Gland Mucosa Lineage: Histopathological Features of Background Gastric Mucosa.

AIMS: Gastric epithelial neoplasm of fundic-gland mucosa lineage (GEN-FGML) has been increasingly recognized in recent years; however, few studies have investigated the histopathology of the background gastric mucosa surrounding the lesion. This study clarifies the histopathological features of the background gastric mucosa in GEN-FGML.

METHODS AND

RESULTS

A retrospective analysis was conducted of 30 GEN-FGML lesions (28 patients) diagnosed at our institution between December 2012 and 2023, excluding cases of gastric adenocarcinoma of fundic-gland mucosa type. Patients were classified according to Helicobacter pylori infection status, and clinicopathological features were compared. The background gastric mucosa was evaluated using the Updated Sydney System (USS). In total, 15 lesions (13 patients) were in the uninfected group, and 15 lesions (15 patients) were in the past H. pylori infection group (i.e., the infected group); no lesions from patients with current infection were included. In the uninfected group, none of the lesions showed histopathological atrophy or intestinal metaplasia. Conversely, histopathological atrophy was observed in 12 lesions in the infected group. Although 86.7% (13/15 lesions) of the infected cases were endoscopically located in nonatrophic areas, 10 displayed mild histopathological atrophy (USS 1+).

CONCLUSION

Oxyntic gland adenoma and gastric adenocarcinoma of fundic-gland type arise predominantly from mildly atrophic mucosa with preserved fundic glands in previously infected stomachs, and, albeit less frequently, from severely atrophic mucosa. During routine endoscopic examinations, careful observation of the fundic gland is warranted regardless of the presence of background mucosal atrophy.