Case Report
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jul 14, 2018; 24(26): 2915-2920
Published online Jul 14, 2018. doi: 10.3748/wjg.v24.i26.2915
Gastric adenocarcinoma of fundic gland type with signet-ring cell carcinoma component: A case report and review of the literature
Keita Kai, Masaaki Satake, Osamu Tokunaga
Keita Kai, Department of Pathology, Saga University Hospital, Saga 849-8501, Japan
Masaaki Satake, Department of Gastroenterology, Koga Hospital 21, Kurume 839-0801, Japan
Osamu Tokunaga, Department of Pathology, Shin Koga Hospital, Kurume 830-8577, Japan
Author contributions: Kai K is the main author of this article; Satake M was attending doctor and performed endoscopic submucosal dissection; Kai K and Tokunaga O performed pathological diagnosis; Tokunaga O and Satake M reviewed the manuscript; all authors have read and approved the final manuscript.
Informed consent statement: Written informed consent was obtained.
Conflict-of-interest statement: The authors declare that there are no conflicts of interest.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Keita Kai, MD, PhD, Associate Professor, Department of Pathology, Saga University Hospital, Nabeshima 5-1-1, Saga City, Saga 849-8501, Japan.
Telephone: +81-952-343264 Fax: +81-952-342055
Received: April 13, 2018
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.

Keywords: Gastric adenocarcinoma of fundic gland type, Endoscopic submucosal dissection, Helicobacter pylori, Intestinal metaplasia, Signet-ring cell carcinoma

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.