Objective To investigate the clinicopathological characteristics of oxyntic gland adenoma (OGA) and gastric adenocarcinoma of the fundic gland type (GA-FG).

Methods  Six cases of fundic gland-type tumors (three OGA and three GA-FG) diagnosed at the Fujian Cancer Hospital between August 2020 and February 2023 were retrospectively analyzed. The clinical data, endoscopic features, pathological characteristics, immunohistochemical results, treatment, and prognosis were analyzed.

Results  Six patients with an average age of 57 years, including one male and five females, were mainly affected in the gastric fundus and body, with the superficial elevated type being the most common. The pathological features of gastric gland-type tumors are mostly located in the deep layer of the gastric mucosa, showing a disordered glandular structure mainly composed of chief cell-type cells. There were three cases of OGA and three cases of GA-FG. Immunohistochemical results showed that pepsinogen 1 was positive in five cases, mucin 6 (MUC6) in five cases, synaptophysin (Syn) in six cases, chromogranin (CgA) was negative in all cases, and Ki-67 was less than 10%.

Conclusions  The incidences of OGA and GA-FG are low, and there is no obvious endoscopic specificity. Endoscopy physicians have an insufficient understanding, which can easily lead to misdiagnoses and missed diagnoses. Immunohistochemistry is helpful for the differential diagnosis, and endoscopic mucosal resection or stripping is the preferred treatment option.