title: Massive gastric juvenile-type polyposis: a clinicopathological analysis of 22 cases.
abstract: OBJECTIVE
  Massive gastric polyposis is a rare entity that is often associated with juvenile polyposis syndrome (JPS). The aim of this study was to evaluate the clinicopathological features of 22 patients with abundant gastric juvenile-type or hyperplastic-like polyps.
  
  
  RESULTS
  The study included 12 males and 10 females with a median age of 48 years (range: 13-79 years). Fourteen (64%) patients carried a diagnosis of JPS, and three had prior gastrointestinal adenocarcinomas. Patients without known JPS presented at an older median age (60 years versus 40 years; P = 0.0068). Clinical symptoms included nausea, vomiting, and abdominal pain; 23% of patients were asymptomatic. Eighteen cases showed complete or near-complete carpeting of the gastric mucosa by innumerable polyps, ranging from a few millimetres to ~100 mm. Most polyps formed long, bulbous projections and had characteristic histological features, including a smooth outer contour, prominent stromal oedema, and widely spaced, often cystically dilated glands lined by foveolar epithelium; some polyps had less stroma and more hyperplastic foveolar epithelium. All had normal underlying or adjacent mucosa. Four (18%) cases harboured adenocarcinoma, and seven (32%) others showed dysplasia. SMAD4 immunohistochemical staining showed patchy loss in polyps from 19 of 20 cases tested. Five of six (84%) patients tested had a germline SMAD4 mutation.
  
  
  CONCLUSIONS
  Massive gastric juvenile-type polyposis can occur in patients with and without known JPS, and may mimic different conditions, such as other polyposis syndromes and Ménétrier disease. Pathologists play an important role in disease classification, as some patients lack a family or personal history of JPS, have few if any colonic polyps, and may not harbour diagnostic germline mutations.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY, USA.
authors.forename: Raul S
authors.identifier: http://orcid.org/0000-0001-5526-4220
authors.initials: RS
authors.lastname: Gonzalez
authors.affiliation: Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, USA.
authors.forename: Volkan
authors.initials: V
authors.lastname: Adsay
authors.affiliation: Division of Anatomic Pathology, Department of Pathology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Rondell P
authors.initials: RP
authors.lastname: Graham
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
authors.forename: Stuti G
authors.initials: SG
authors.lastname: Shroff
authors.affiliation: Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL, USA.
authors.forename: Michael M
authors.initials: MM
authors.lastname: Feely
authors.affiliation: Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Drage
authors.affiliation: Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, USA.
authors.forename: David N
authors.initials: DN
authors.lastname: Lewin
authors.affiliation: Department of Pathology, University of Utah, Salt Lake City, UT, USA.
authors.forename: Eric A
authors.initials: EA
authors.lastname: Swanson
authors.affiliation: Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY, USA.
authors.forename: Rhonda K
authors.initials: RK
authors.lastname: Yantiss
authors.affiliation: Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, USA.
authors.forename: Pelin
authors.initials: P
authors.lastname: Bağci
authors.affiliation: Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, USA.
authors.forename: Alyssa M
authors.initials: AM
authors.lastname: Krasinskas
mesh_terms: D000230:Adenocarcinoma / Q000453:epidemiology / Q000209:etiology; D018256:Adenomatous Polyps / Q000235:genetics / Q000473:pathology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D051901:Smad4 Protein / Q000235:genetics; D013274:Stomach Neoplasms / Q000235:genetics / Q000473:pathology*; D055815:Young Adult
chemical_list: D051901:Smad4 Protein
keywords: Ménétrier disease; SMAD4; gastric polyps; genetics; juvenile polyposis syndrome