title: Endoscopic piecemeal mucosal resection of large colorectal tumors.
abstract: OBJECTIVE
  Since endoscopic en bloc resection of large and sessile tumors is technically difficult, endoscopic en bloc piecemeal mucosal resection (EPMR) is usually chosen for resection of such tumors. Tumors resected by EPMR are, however, difficult to evaluate histologically. The aim of this study was to evaluate the safety and effectiveness of EPMR.
  
  
  METHODS
  We removed 30 large colorectal tumors in 30 patients by EPMR between 1992-2000. Endoscopic examination was repeated at 3, 6 and 12 months and later on after initial endoscopic resection. Patients in whom no residual tumor was found by both endoscopic and histologic examination were considered to be "cured".
  
  
  RESULTS
  Histological examination of the resected tumor tissues revealed malignancy in 43.3% (13/30). Three patients had invasive malignant tumors and underwent surgery. Following complete endoscopic resection, recurrences were observed in 2 patients with benign tumors, which were resected by additional endoscopic resection. All patients including the two with non-invasive malignant tumors remain free from recurrence during a mean follow-up period of 45.2 months (range, 3-104 months). Bleeding was the only complication and was seen in one patient (3.3%; 1/30), which was treated by endoscopic clipping.
  
  
  CONCLUSIONS
  EPMR of benign or non-invasive large malignant tumors is a safe and effective procedure. Complete excision of large, sessile and non-invasive tumors is possible, although complete removal by EPMR cannot be verified histologically.
authors.affiliation: Third Department of Internal Medicine, University of Occupational and Environmental Health Japan, School of Medicine, Kitakyusyu, Japan.
authors.forename: Keiichiro
authors.initials: K
authors.lastname: Kume
authors.forename: Ikuo
authors.initials: I
authors.lastname: Murata
authors.forename: Ichiro
authors.initials: I
authors.lastname: Yoshikawa
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yamasaki
authors.forename: Kikuo
authors.initials: K
authors.lastname: Kanda
authors.forename: Makoto
authors.initials: M
authors.lastname: Otsuki
mesh_terms: D000236:Adenoma / Q000473:pathology / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000473:pathology / Q000601:surgery*; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000473:pathology / Q000601:surgery*; D016145:Endoscopy, Digestive System / Q000379:methods*; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D012189:Retrospective Studies