Twenty cases of gastric adenocarcinoma of the fundic gland type

Background: Gastric adenocarcinoma of the fundic gland type is a new subtype of gastric adenocarcinoma. In 2019, the World Health Organization (WHO) listed gastric adenocarcinoma of the fundic gland type (GA-FG) as a new and rare gastric tumour with a low incidence due to the small number of cumulative cases worldwide. Twenty cases of GA-FG found in our centre were retrospectively analysed to improve the diagnostic ability of endoscopy and pathology in this disease.

Objective: To investigate the clinicopathological features of fundus-derived gastric tumours and to improve the understanding of and diagnostic accuracy of endoscopy for this disease.

Methods: The clinicopathological characteristics of 20 GA-FG cases between 2018 and 2022 were analysed using clinical and follow-up data and endoscopic, immunohistochemical, and pathological morphology characteristics.

Results: In all cases, GA-FG was found in the fundus and the body of the stomach. In total, there were 19 patients with 20 lesions, with most of the patients having a single lesion. One patient had multiple lesions, and another patient had complications from signet ring cell carcinoma (SRCC). All lesions occurred in non-atrophic areas, and 10 patients had gastric fundic gland polyps simultaneously. There were 14 cases of gastric fundus adenocarcinoma and 6 cases of acid-secreting adenoma. Fourteen lesions were treated with endoscopic submucosal dissection (ESD), without recurrence or metastasis during the follow up; 6 patients were followed up for observation, 2 of whom showed no lesions after the first biopsy by gastric endoscopy, and 4 of whom showed no significant changes.

Conclusions: The incidence rate for GA-FG lesions may be underestimated due to their benign course. ESD seems to be an adequate treatment for GA-FG.

Main points: Gastric adenocarcinoma of the fundic gland type (GA-FG) is located in the fundus and body of the stomach. All lesions occur in non-atrophic areas, and almost one-half involve gastric fundus polyps simultaneously. GA-FG lesions typically follow a benign disease course. ESD seems to be an adequate treatment for GA-FG.