Case Report
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jan 7, 2021; 27(1): 129-142
Published online Jan 7, 2021. doi: 10.3748/wjg.v27.i1.129
Spontaneous regression of gastric gastrinoma after resection of metastases to the lesser omentum: A case report and review of literature
Takeshi Okamoto, Takaaki Yoshimoto, Nobuyuki Ohike, Aoi Fujikawa, Takayoshi Kanie, Katsuyuki Fukuda
Takeshi Okamoto, Takaaki Yoshimoto, Katsuyuki Fukuda, Department of Gastroenterology, St. Luke's International Hospital, Tokyo 104-8560, Japan
Nobuyuki Ohike, Department of Pathology, Shizuoka Cancer Center, Shizuoka 411-8777, Japan
Aoi Fujikawa, Department of Surgery, St. Luke’s International Hospital, Tokyo 104-8560, Japan
Takayoshi Kanie, Department of Cardiology, St. Luke’s International Hospital, Tokyo 104-8560, Japan
Author contributions: Okamoto T cared for the patient, performed endoscopic procedures, wrote the manuscript, and reviewed the literature; Yoshimoto T cared for the patient and contributed to manuscript drafting; Ohike N interpreted the pathological findings and contributed to manuscript drafting; Fujikawa A performed the surgical procedure and contributed to manuscript drafting; Kanie T cared for the patient, performed cardiology procedures and contributed to manuscript drafting; Fukuda K provided oversight for the manuscript and revised the manuscript for important intellectual content; and all authors issued final approval for the version to be submitted.
Informed consent statement: The patient has provided written informed consent for the publication of this article and associated images.
Conflict-of-interest statement: The authors have no financial disclosures or conflicts of interest to declare.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (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: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Takeshi Okamoto, MD, Staff Physician, Department of Gastroenterology, St. Luke's International Hospital, 9-1 Akashicho, Chuo-ku, Tokyo 104-8560, Japan. tak@afia.jp
Received: October 11, 2020
Peer-review started: October 11, 2020
First decision: November 23, 2020
Revised: November 28, 2020
Accepted: December 16, 2020
Article in press: December 16, 2020
Published online: January 7, 2021
Abstract
BACKGROUND

Gastric gastrinoma and spontaneous tumor regression are both very rarely encountered. We report the first case of spontaneous regression of gastric gastrinoma.

CASE SUMMARY

A 37-year-old man with a 9-year history of chronic abdominal pain was referred for evaluation of an 8 cm mass in the lesser omentum discovered incidentally on abdominal computed tomography. The tumor was diagnosed as grade 2 neuroendocrine neoplasm (NEN) on endoscopic ultrasound-guided fine-needle aspiration. Screening esophagogastroduodenoscopy revealed a 7 mm red polypoid lesion with central depression in the gastric antrum, also confirmed to be a grade 2 NEN. Laparoscopic removal of the abdominal mass confirmed it to be a metastatic gastrinoma lesion. The gastric lesion was subsequently diagnosed as primary gastric gastrinoma. Three months later, the gastric lesion had disappeared without treatment. The patient remains symptom-free with normal fasting serum gastrin and no recurrence of gastrinoma during 36 mo of follow-up.

CONCLUSION

Gastric gastrinoma may arise as a polypoid lesion in the gastric antrum. Spontaneous regression can rarely occur after biopsy.

Keywords: Neuroendocrine neoplasm, Functional tumor, Biopsy, Gastrin, Stomach, Case report

Core Tip: Gastrinoma is a functional neuroendocrine tumor which can cause refractory gastrointestinal symptoms. We present a rare case of gastrinoma originating in the stomach, with metastasis to the lesser omentum. Tumors including neuroendocrine tumors are rarely known to regress spontaneously following biopsy or surgical insult. This is the first report of spontaneous regression of a gastric gastrinoma. We also review the literature on gastric gastrinoma, gastrinoma arising in the lesser omentum, and spontaneous regression of gastrinomas and other neuroendocrine tumors.