Clinicopathologic features and endoscopic treatment of superficially spreading colorectal neoplasms larger than 20 mm

Gastrointest Endosc. 2001 Jul;54(1):62-6. doi: 10.1067/mge.2001.115729.


Background: A colorectal neoplasm that spreads superficially over the mucosa is known as a laterally spreading tumor. The clinicopathologic features of these large lesions and the efficacy and safety of endoscopic mucosal resection (EMR) were studied retrospectively.

Methods: Surgically or endoscopically resected laterally spreading tumors larger than 20 mm in diameter were studied. Lesions were divided into 2 macroscopic subtypes: F-type, composed of superficially spreading lesions with a flat and smooth surface, and G-type, composed of superficially spreading aggregates of nodules that form relatively flat, broad-based lesions with granulonodular and uneven surfaces.

Results: Thirty-three lesions were of the F-type and 87 the G-type. G-type (mean +/- SD, 35.3 +/- 11.4 mm) lesions were significantly larger (p < 0.01) than F-type (26.0 +/- 7.2 mm) lesions. F-type lesions had a significantly higher frequency of invasive cancer (27.2%) than G-types (10.3%)(p < 0.05). Of the 120 lesions, 81 (67.5%) were resected endoscopically. Patients with 78 of these lesions were followed postoperatively for 60.8 +/- 20.1 months. The rate of local recurrence of endoscopically treated tumors as determined at colonoscopy was 7.4% (6/78). These lesions were completely resected endoscopically. Distant metastases were not detected. Thirteen (16.0%) patients had local bleeding after EMR that was stopped endoscopically. Microperforation of the colonic wall as a result of EMR was diagnosed in 1 (1.2%) of 81 cases.

Conclusions: Laterally spreading tumors larger than 20 mm, especially those of the G-type, have a low rate of invasion despite their relatively large size. The F-type lesion has a higher malignant potential than the G-type. EMR is an effective and safe treatment for the large laterally spreading tumor.

MeSH terms

  • Adenoma / pathology
  • Adenoma / surgery*
  • Carcinoma in Situ / pathology
  • Carcinoma in Situ / surgery*
  • Colonic Diseases / diagnosis
  • Colonic Diseases / pathology
  • Colonoscopy*
  • Colorectal Neoplasms / pathology
  • Colorectal Neoplasms / surgery*
  • Humans
  • Intestinal Mucosa / pathology
  • Intestinal Mucosa / surgery*
  • Intestinal Perforation / diagnosis
  • Intestinal Perforation / pathology
  • Neoplasm Recurrence, Local / diagnosis
  • Neoplasm Recurrence, Local / pathology
  • Postoperative Complications / diagnosis
  • Postoperative Complications / pathology
  • Postoperative Hemorrhage / diagnosis
  • Postoperative Hemorrhage / pathology
  • Retrospective Studies