Introduction: Gastric adenocarcinoma of the fundic gland type (GA-FG) is a newly described entity that is characterized by well-differentiated neoplasm with unclear etiopathogenesis.
Patient concerns: A 60-year-old Chinese man was referred to our hospital for abdominal distension.
Diagnosis: Esophagogastroduodenoscopy (EGD) showed a depressed lesion found using in the greater curvature of the stomach. The pathological diagnosis of the biopsy specimens indicated that the tumor was GA-FG (chief cell predominant type, GA-FG-CCP).
Interventions: Endoscopic submucosal dissection (ESD) was performed. The histopathological examination of the ESD specimen revealed gastric hyperplasia of the fundic gland type around the adenocarcinoma cells.
Outcomes: The surgical outcomes were good. The EGD showed a scar with no recurrence, and no symptoms were observed 1 year postoperatively during the follow-up.
Conclusion: We present a rare case of a depressed lesion with a pathogenic expression suggesting gastric hyperplasia of the fundic gland type around the adenocarcinoma cells. Considering the origin of oxyntic mucosa, we consider that it may develop into GA-FG. To understand this issue better, similar cases should be monitored in the future.