Category: Stomach

P2630 - Identifying the GAPPS in Hereditary Gastric Polyposis Syndromes

Tuesday, October 9
10:30 AM – 4:00 PM

Category: Stomach       Sub-Category: Clinical Vignettes/Case Reports

Alyssa Anderson, MD1, Linnea Swanson, BA2, Regina Plummer, DO1, James Abraham, MD1

1University of Minnesota, Minneapolis, MN; 2University of Minnesota Medical School, Minneapolis, MN

Abstract Body: Gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) is a newly-described and rarely reported hereditary syndrome with pathognomonic endoscopic findings, specific mutations of the APC gene, and an association with gastric adenocarcinoma. Here we present a case of GAPPS to highlight the importance of a detailed family history in the setting of incidentally-discovered profound gastric polyposis and to discuss management options.

A 62-year-old male with coronary artery disease presented to our institution for evaluation of gastric polyposis following routine upper endoscopy for evaluation of iron deficiency anemia. Family history included a daughter who died at age 32 from Stage IV gastric adenocarcinoma in the setting of similar gastric polyposis; there was no known family history of colon cancer or other associated Lynch Syndrome cancers. Gastric polyposis preceded PPI therapy. Given unexplained iron deficiency, EGD and colonoscopy were performed. EGD revealed diffuse profound fundic gland-like polyps heaped up throughout the gastric fundus, cardia, and body with notable sparing of the antrum and duodenum, highly suspicious for GAPPS (Figure 1). Colonoscopy was unremarkable. A CT scan did not reveal any lesions suspicious for extra-intestinal gastrinoma. Consultation with a genetic counselor confirmed the presence of APC gene mutation c.-191T>C, consistent with GAPPS. The patient ultimately underwent total gastrectomy (Figure 2). Histology revealed numerous fundic gland polyps, several of which contained focal adenomatous transformation with low grade dysplasia (Figure 3). Post-operative recovery was uneventful.

GAPPS is a unique hereditary gastric polyposis syndrome with classic endoscopic findings and a significantly increased risk of gastric adenocarcinoma. The risk of gastric adenocarcinoma can be managed with endoscopic surveillance or pre-emptive total gastrectomy. Efficacy of endoscopic surveillance is fairly limited given the significant polyp burden involved and the unclear interval between exams; risk of interval cancer progression is non-negligible. All first-degree relatives of patients with GAPPS should be referred for genetic counseling to determine their individual risk. We present this case to generate awareness of the importance of accurately recognizing a possible polyposis syndrome, thoughtful history-taking with attention to family history of cancer, and timely tertiary referral for surveillance and/or surgical management.

Disclosures: Does Not Disclose

Alyssa Anderson indicated no relevant financial relationships.
Linnea Swanson indicated no relevant financial relationships.
Regina Plummer indicated no relevant financial relationships.
James Abraham indicated no relevant financial relationships.

Upper endoscopy image revealing fundic gland-like polyps carpeting the proximal stomach with sparing of the antrum.

Gross pathology images of the stomach post-total gastrectomy notable for diffuse polyposis with antral sparing.

Histology revealing typical fundic gland polyp epithelium (image right) with adenomatous transformation (image left).

Citation: Alyssa Anderson, MD; Linnea Swanson, BA; Regina Plummer, DO; James Abraham, MD. IDENTIFYING THE GAPPS IN HEREDITARY GASTRIC POLYPOSIS SYNDROMES. Program No. P2630. ACG 2018 Annual Scientific Meeting Abstracts. Philadelphia, Pennsylvania: American College of Gastroenterology.

Alyssa Anderson

Gastroenterology Fellow
University of Minnesota
Minneapolis, Minnesota