title: Endoscopic partial resection with the unroofing technique for reliable tissue diagnosis of upper GI subepithelial tumors originating from the muscularis propria on EUS (with video).
abstract: BACKGROUND
  There is a growing body of evidence that a pathological diagnosis is necessary for small (<3 cm in diameter), asymptomatic, hypoechoic, subepithelial tumors (SETs) originating from the muscularis propria on EUS. However, the diagnostic efficacy of current tissue sampling techniques appears to be limited.
  
  
  OBJECTIVE
  To evaluate the diagnostic yield and safety of endoscopic partial resection using the unroofing technique (EPR-UT) in a subset of patients.
  
  
  METHODS
  A prospective case series.
  
  
  METHODS
  A single tertiary-care referral center.
  
  
  METHODS
  Between August 2007 and March 2009, 16 patients with hypoechoic SETs of <3 cm in diameter, originating from the muscularis propria on EUS (14 gastric and 2 esophageal lesions), underwent EPR-UT.
  
  
  METHODS
  The overlying mucosa was removed by using the unroofing technique using a conventional snare with electrical current to expose the tumor sufficiently. Next, the exposed tumor was partially resected by snaring.
  
  
  METHODS
  The diagnostic yield and safety of this method.
  
  
  RESULTS
  EPR-UT provided specimens that were sufficient for a diagnosis and the assessment of risk for malignancy in 15 out of 16 cases (diagnostic yield 93.7% [95% CI, 80.4%-100.0%]). The pathological diagnoses were leiomyoma (7 of 15, 46.6%), GI stromal tumor (6 of 15, 40.0%), aberrant pancreas (1 of 15, 6.6%), and well-differentiated neuroendocrine carcinoma (1 of 15, 6.6%). Six cases with GI stromal tumor were classified as very low risk for malignant potential (mitotic index <5/50 high-power fields). Procedural blood oozing was relatively common (9 of 16, 56.0% [95% CI, 33.0%-77.0%]); however, this minor complication was easily controlled by argon plasma coagulation. There were no procedure-related major complications (0 of 16, 0% [95% CI, 0.0%-23.0%]).
  
  
  CONCLUSIONS
  Single-center, noncomparative study with small sample size.
  
  
  CONCLUSIONS
  EPR-UT appears to be simple, safe, and effective for determining the definite pathological diagnosis and assessing malignant potential of small, hypoechoic SETs originating from the muscularis propria on EUS.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Soon Chun Hyang University College of Medicine, Cheonan Hospital, Cheonan, Korea.
authors.forename: Chang Kyun
authors.initials: CK
authors.lastname: Lee
authors.forename: Il-Kwun
authors.initials: IK
authors.lastname: Chung
authors.forename: Suck-Ho
authors.initials: SH
authors.lastname: Lee
authors.forename: Sae Hwan
authors.initials: SH
authors.lastname: Lee
authors.forename: Tae Hoon
authors.initials: TH
authors.lastname: Lee
authors.forename: Sang-Heum
authors.initials: SH
authors.lastname: Park
authors.forename: Hong-Soo
authors.initials: HS
authors.lastname: Kim
authors.forename: Sun-Joo
authors.initials: SJ
authors.lastname: Kim
authors.forename: Hyun-Deuk
authors.initials: HD
authors.lastname: Cho
mesh_terms: D001706:Biopsy / Q000379:methods; D002828:Choristoma / Q000473:pathology*; D004067:Digestive System Neoplasms / Q000473:pathology*; D019160:Endosonography; D004945:Esophagoscopy; D005773:Gastroscopy; D006801:Humans; D009092:Mucous Membrane / Q000601:surgery*; D010179:Pancreas; D011446:Prospective Studies; D013272:Stomach Diseases / Q000473:pathology*; D014741:Video Recording