Published online Jul 14, 2018. doi: 10.3748/wjg.v24.i26.2915
Peer-review started: April 13, 2018
First decision: May 21, 2018
Revised: May 22, 2018
Accepted: June 9, 2018
Article in press: June 9, 2018
Published online: July 14, 2018
A depressed lesion was found at a gastric angle of 76-year-old Japanese woman by esophagogastroduodenoscopy. Four years prior, she was diagnosed with a Helicobacter pylori infection but no eradication was performed. The pathological diagnosis of biopsy specimens was signet-ring cell carcinoma. Endoscopic submucosal dissection (ESD) was performed. Histopathological examination of the ESD specimen revealed proliferation of well-differentiated tubular adenocarcinoma mimicking fundic gland cells at the deep layer of the lamina propria mucosae. These tumor cells expressed focally pepsinogen-I, diffusely MUC6, and scattered H+/K+ ATPase according to immunohistochemistry. Therefore, we diagnosed this tumor as gastric adenocarcinoma of fundic gland type (GA-FG). Adjacent to the GA-FG, proliferation of signet-ring cell carcinoma which diffusely expressed MUC 2 and MUC 5AC was observed. Intestinal metaplasia was focally observed in the surrounding mucosa of the signet-ring cell carcinoma. To the best of our knowledge, this is the first case report of GA-FG with a signet-ring cell carcinoma component. The origin of signet-ring cell carcinoma, i.e., whether it accidentally arose from a non-neoplastic mucosa and coexisted with the GA-FG or dedifferentiated from the GA-FG is unclear at present. We expect the accumulation of similar cases and further analysis to clarify this issue.
Core tip: Gastric adenocarcinoma of fundic gland type is a very rare variant of a well-differentiated gastric adenocarcinoma. To the best of our knowledge, this is the first case report of gastric adenocarcinoma of fundic gland type with a signet-ring cell carcinoma component.