title: Natural history of asymptomatic small gastric subepithelial tumors.
abstract: To assess the natural history of gastric subepithelial tumors (SETs) of ≤30 mm in size and to determine their optimal management.
  
  
  
  Definitive guidelines have not been formulated for the management of small gastric SETs, owing to a lack of knowledge of their natural history and insufficient long-term follow-up.
  
  
  
  We retrospectively reviewed the upper endoscopy and/or endoscopic ultrasound results of 989 tumors diagnosed as gastric SETs of ≤30 mm in size between July 1997 and October 2008 with a minimal follow-up of 3 months. A gastric SET was defined as a mass covered with normal appearing mucosa on upper endoscopy and a tumor located in the second, third, or fourth layer on endoscopic ultrasound.
  
  
  
  Of the 989 SETs in 948 patients, 84 (8.5%) showed significant changes in size, and/or echogenicity, and/or morphology at a median 24 months (range, 3 to 123 mo). Estimated growth rates differed significantly by initial size (<10 mm, 0.14 mm/mo; 10 to 20 mm, 0.22 mm/mo; 20 to 30 mm, 0.31 mm/mo; P=0.003). Twenty-five patients with tumors showing changes in size and/or echogenicity underwent surgical/endoscopic resection; of these, 19 patients were diagnosed with gastrointestinal stromal tumors (GISTs), of which 3 patients were considered at high risk, 4 at intermediate risk, 10 at low risk, and 2 at very low risk. In a univariate analysis, GISTs showed a significant change in tumor size during follow-up compared with other benign tumors (P=0.037). However, multivariate analysis did not show a statistical significance in size change between GISTs and other benign tumors (hazard ratio 1.754; 95% CI, 0.575 to 5.291; P=0.326).
  
  
  
  Only 8.5% of gastric SETs of ≤30 mm in size showed significant changes at a median 24 months. SETs of 10 to 30 mm in size grew significantly more rapidly than SETs <10 mm.
authors.affiliation: Department of Gastroenterology, Asan Medical Center, Asan Digestive Disease Research Institute, University of Ulsan College of Medicine, Songpa-gu, Seoul, Korea.
authors.forename: Mi-Young
authors.initials: MY
authors.lastname: Kim
authors.forename: Hwoon-Yong
authors.initials: HY
authors.lastname: Jung
authors.forename: Kee Don
authors.initials: KD
authors.lastname: Choi
authors.forename: Ho June
authors.initials: HJ
authors.lastname: Song
authors.forename: Jeong Hoon
authors.initials: JH
authors.lastname: Lee
authors.forename: Do Hoon
authors.initials: DH
authors.lastname: Kim
authors.forename: Kwi-Sook
authors.initials: KS
authors.lastname: Choi
authors.forename: Gin Hyug
authors.initials: GH
authors.lastname: Lee
authors.forename: Jin-Ho
authors.initials: JH
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D018450:Disease Progression; D019160:Endosonography; D005260:Female; D005753:Gastric Mucosa / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D046152:Gastrointestinal Stromal Tumors / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D005773:Gastroscopy / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D013270:Stomach / Q000000981:diagnostic imaging / Q000473:pathology; D013274:Stomach Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D055815:Young Adult