Invasion depth diagnosis of depressed type early colorectal cancers by combined use of videoendoscopy and chromoendoscopy

Gastrointest Endosc. 1998 Oct;48(4):362-70. doi: 10.1016/s0016-5107(98)70004-5.


Background: Depressed type early colorectal cancers are found less frequently than other polypoid cancers although they have a higher submucosal invasion rate. Recently videocolonoscopy and chromoendoscopy have become available and precise descriptions of these lesions are now routine. Because endoscopic mucosal resection is designated for intramucosal and focally extended submucosal (m-sm1) cancers, an evaluation of the characteristic findings indicating invasion depth with these modalities is important.

Methods: Between January 1991 and March 1996, 64 depressed type early colorectal cancers were detected and treated. When a faint abnormality of the mucosa was suspected by routine videocolonoscopy, 0.1% of indigo carmine solution was sprayed on the mucosal surface (chromoendoscopy). Colonoscopic findings of m-sm1 cancers and moderately and massively extended submucosal (sm2-3) cancers were retrospectively reviewed and compared with confirmed histologic findings.

Results: Characteristic colonoscopic findings needed for surgical operation were as follows: (1) expansion appearance, (2) deep depression surface, (3) irregular bottom of depression surface, and (4) folds converging toward the tumor. By using these findings, the invasion depth of depressed type early colorectal cancers could be correctly determined in 58 of 64 lesions (91%).

Conclusions: Characteristic colonoscopic findings obtained by a combination of videocolonoscopy and chromoendoscopy are useful for determination of the invasion depth of depressed type colorectal cancers, an essential factor in choosing a treatment modality.

MeSH terms

  • Colon / pathology
  • Colonoscopy / methods*
  • Colorectal Neoplasms / diagnosis*
  • Colorectal Neoplasms / pathology
  • Coloring Agents
  • Female
  • Humans
  • Indigo Carmine
  • Intestinal Mucosa / pathology
  • Male
  • Middle Aged
  • Neoplasm Invasiveness
  • Predictive Value of Tests
  • Rectum / pathology
  • Retrospective Studies
  • Sensitivity and Specificity
  • Video Recording


  • Coloring Agents
  • Indigo Carmine