Published online Feb 25, 2016. doi: 10.4253/wjge.v8.i4.244
Peer-review started: August 6, 2015
First decision: September 23, 2015
Revised: December 20, 2015
Accepted: January 5, 2016
Article in press: January 7, 2016
Published online: February 25, 2016
Processing time: 208 Days and 17.5 Hours
Gastric adenocarcinoma of fundic gland type (GA-FG) with chief cell differentiation was recently proposed as an extremely rare type of gastric adenocarcinoma. Here, we report 4 cases of GA-FG with chief cell differentiation. Endoscopic features included a submucosal tumor shape or a flat shape, whitish discoloration and dilated vessels on the surface. The tumors were located in the upper or middle third of the stomach. All cases were preoperatively diagnosed as GA-FG by biopsy, and endoscopic submucosal dissection was performed. Resected specimens revealed well-differentiated adenocarcinomas resembling chief cells. Tumor cells were diffusely positive for pepsinogen-I, but partially positive for H+/K+-ATPase in scattered locations around the tumor margin. Despite the presence of minimal invasion of the carcinoma into the submucosal layer, which was observed in two cases, neither lymphatic nor venous invasion was detected in any of the cases. Finally, all cases showed less aggressive clinical behavior with low grade malignancy.
Core tip: Gastric adenocarcinoma of fundic gland type (GA-FG) with chief cell differentiation is a new and extremely rare type of gastric adenocarcinoma, and the clinicopathological features of GA-FG have thus not yet been elucidated. In the present study, we discuss 4 cases of GA-FG that displayed low grade malignancy, slow-growth and less aggressive clinical behavior. Endoscopic submucosal dissection was performed and complete tumor resection was confirmed pathologically. None of the patients showed any signs of recurrence during the follow-up periods. We decided to report these rare cases because of their distinct endoscopic and clinicopathological features and unique biological behaviors.