title: Where has the tumor gone? The characteristics of cases of negative pathologic diagnosis after endoscopic mucosal resection.
abstract: OBJECTIVE
  Discrepancies can occur between the histopathological findings from forceps biopsy and endoscopic mucosal resection (EMR), and occasionally in embarrassing cases tumorous tissue is not found at EMR. The aim of the present study was to evaluate the clinical, endoscopic, and histological features of gastric tumors in patients with pathololgically negative findings at EMR.
  
  
  METHODS
  We retrospectively reviewed data from all patients with gastric tumor treated with EMR or endoscopic submucosal dissection (ESD) between August 1999 and April 2007 at our institution, and enrolled into the study patients with no tumor tissue found at mucosal resection. Their biopsy and EMR specimen slides were reviewed by a single pathologist. Patient characteristics, including demographic and clinical features, and the endoscopic appearance of mucosal lesions were evaluated.
  
  
  RESULTS
  Out of 633 patients treated with EMR or ESD, 20 patients (3.2 %) were included. The mean +/- SD maximal dimension of the mucosal lesions was 6.40 +/- 2.19 mm (range 3 - 10). Mean number of forceps biopsy fragments was 3.80 +/- 1.96 and mean sampling ratio was 2.08 +/- 1.07 mm/fragment. Before resection, histological findings from forceps biopsy were: 13 low grade dysplasias (65.0 %), 2 high grade dysplasias (10.0 %), and 5 intramucosal carcinomas (25.0 %).
  
  
  CONCLUSIONS
  In the case of pathologically negative findings at EMR, tumors might have been small enough to have been removed by the previous forceps biopsy. However, the possibility of sampling error or of a different location should be considered. Furthermore, appropriate communication between endoscopists and pathologists is essential.
authors.affiliation: Department of Internal Medicine, Division of Gastroenterology and Hepatology, Kyungpook National University Hospital, Daegu 700-721, Korea.
authors.forename: E S
authors.initials: ES
authors.lastname: Kim
authors.forename: S W
authors.initials: SW
authors.lastname: Jeon
authors.forename: S Y
authors.initials: SY
authors.lastname: Park
authors.forename: Y D
authors.initials: YD
authors.lastname: Park
authors.forename: Y J
authors.initials: YJ
authors.lastname: Chung
authors.forename: S J
authors.initials: SJ
authors.lastname: Yoon
authors.forename: S Y
authors.initials: SY
authors.lastname: Lee
authors.forename: J Y
authors.initials: JY
authors.lastname: Park
authors.forename: H I
authors.initials: HI
authors.lastname: Bae
authors.forename: C M
authors.initials: CM
authors.lastname: Cho
authors.forename: W Y
authors.initials: WY
authors.lastname: Tak
authors.forename: Y O
authors.initials: YO
authors.lastname: Kweon
authors.forename: S K
authors.initials: SK
authors.lastname: Kim
authors.forename: Y H
authors.initials: YH
authors.lastname: Choi
mesh_terms: D000230:Adenocarcinoma / Q000382:microbiology / Q000473:pathology; D000328:Adult; D000368:Aged; D001706:Biopsy; D003951:Diagnostic Errors; D004210:Dissection / Q000379:methods; D016099:Endoscopy, Gastrointestinal / Q000379:methods; D005260:Female; D005753:Gastric Mucosa / Q000473:pathology* / Q000601:surgery; D016480:Helicobacter pylori / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D011706:Pyloric Antrum / Q000473:pathology; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000382:microbiology / Q000473:pathology*