title: Yield of tissue sampling for subepithelial lesions evaluated by EUS: a comparison between forceps biopsies and endoscopic submucosal resection.
abstract: BACKGROUND
  In most circumstances, subepithelial tumors lack distinct endoscopic and ultrasonographic features. Consequently, definitive diagnosis usually requires tissue acquisition and pathologic confirmation. Establishing a tissue diagnosis is difficult because the yield of forceps biopsies is low. However, prospective data evaluating tissue sampling techniques for subepithelial lesions are currently lacking.
  
  
  OBJECTIVE
  Our purpose was to prospectively determine the diagnostic yield of endoscopic submucosal-mucosal resection (ESMR) compared with forceps biopsy for lesions limited to the submucosa (third endosonographic layer) of the GI tract.
  
  
  METHODS
  A prospective head-to-head comparison was performed.
  
  
  METHODS
  The study was performed in a tertiary care hospital.
  
  
  METHODS
  Study patients were 23 adults with subepithelial lesions limited to the submucosa.
  
  
  METHODS
  All submucosal lesions underwent forceps biopsy followed by endoscopic submucosal resection. Biopsy specimens were obtained with large-capacity "jumbo" forceps. A total of 4 double passes (8 biopsy specimens) were collected from each lesion with use of the bite-on-bite technique. Endoscopic resection was then performed with an electrosurgical snare or cap-fitted endoscopic mucosal resection device.
  
  
  METHODS
  The main outcome measurement was the diagnostic yield of biopsy forceps compared with endoscopic submucosal resection.
  
  
  RESULTS
  Twenty-three patients with lesions limited to the submucosa were identified by endoscopic ultrasonography. All lesions underwent forceps biopsy followed by ESMR. The diagnostic yield of the jumbo forceps biopsy was 4 of 23 (17%), whereas the diagnostic yield of ESMR was 20 of 23 (87%) (P = .0001, McNemar test).
  
  
  CONCLUSIONS
  In the evaluation of subepithelial lesions limited to the submucosa, ESMR has a significantly higher diagnostic yield than jumbo forceps biopsy with use of the bite-on-bite technique.
authors.affiliation: Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239-3098, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Cantor
authors.forename: Raquel E
authors.initials: RE
authors.lastname: Davila
authors.forename: Douglas O
authors.initials: DO
authors.lastname: Faigel
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D016099:Endoscopy, Gastrointestinal / Q000379:methods; D019160:Endosonography; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013525:Surgical Instruments