Magnifying colonoscopy or “ultrahigh” magnifying colonoscopy: that is the question

Abstract

To the Editor: We read with great interest the article by Sasajima et al.1Sasajima K. Kudo S.E. Inoue H. et al.Real-time in vivo virtual histology of colorectal lesions when using the endocytoscopy system.Gastrointest Endosc. 2006; 63: 1010-1017Abstract Full Text Full Text PDF PubMed Scopus (125) Google Scholar In our opinion, there are some points that still need to be clarified to prove the efficacy of the endocytoscopy system (E-C system). Sasajima et al1Sasajima K. Kudo S.E. Inoue H. et al.Real-time in vivo virtual histology of colorectal lesions when using the endocytoscopy system.Gastrointest Endosc. 2006; 63: 1010-1017Abstract Full Text Full Text PDF PubMed Scopus (125) Google Scholar insist that the E-C system is superior to the current magnifying colonoscopy, because it provides information not only on structural atypia but also cellular atypia. However, because they applied chromoendoscopy with magnifying observation before endocytoscopy, the results of a pit-pattern diagnosis in comparison with endocytoscopy would be needed to prove the efficacy and the superiority of the E-C system, which takes much more time and needs a pathologist, together with the endoscopist, for real-time diagnosis. Furthermore, it seems to be inappropriate to include normal mucosa for analysis, especially for distinction of non-neoplasia and neoplasia, because normal mucosa could be easily diagnosed correctly by conventional colonoscopy. In addition, Sasajima et al1Sasajima K. Kudo S.E. Inoue H. et al.Real-time in vivo virtual histology of colorectal lesions when using the endocytoscopy system.Gastrointest Endosc. 2006; 63: 1010-1017Abstract Full Text Full Text PDF PubMed Scopus (125) Google Scholar state that the E-C system can correctly diagnose low-grade adenoma, high-grade adenoma, and invasive cancer; therefore, it would undoubtedly be useful for determining endoscopic or surgical treatment. Clinically, however, it is not necessary to distinguish low-grade adenoma and high-grade adenoma endoscopically, because they are not associated with lymph-node metastasis (LNM) and thus are amenable to endoscopic resection. Furthermore, the depth of submucosal invasion in invasive colorectal cancer is a significant predictive factor for LNM, and the minimum depth of cases that displayed LNM was 1000 μm.2Kitajima K. Fujimori T. Fujii S. et al.Correlations between lymph node metastasis and depth of submucosal invasion in submucosal invasive colorectal carcinoma: a Japanese collaborative study.J Gastroenterol. 2004; 39: 534-543Crossref PubMed Scopus (474) Google Scholar The Paris endoscopic classification has also determined 1000 μm as the cutoff limit between sm1 and sm2 stages.3The Paris endoscopic classification of superficial neoplastic lesions: esophagus, stomach, and colon: November 30 to December 1, 2002.Gastrointest Endosc. 2003; 58: S3-S43Abstract Full Text Full Text PDF PubMed Scopus (1635) Google Scholar Kudo et al4Kudo S. Tamegai Y. Yamano H. et al.Endoscopic mucosal resection of the colon: the Japanese technique.Gastrointest Endosc Clin N Am. 2001; 11: 519-535PubMed Google Scholar also reported that lesions that only minimally invaded the submucosa without vessel invasion (sm1a and sm1b, without vessel invasion) could be curatively treated by EMR.4Kudo S. Tamegai Y. Yamano H. et al.Endoscopic mucosal resection of the colon: the Japanese technique.Gastrointest Endosc Clin N Am. 2001; 11: 519-535PubMed Google Scholar Therefore, a correct differential diagnosis of adenoma and invasive cancer as the investigators describe is not sufficient to choose endoscopic or surgical treatment. Real-time in vivo virtual histology of colorectal lesions when using the endocytoscopy systemGastrointestinal EndoscopyVol. 63Issue 7PreviewThe histological findings of GI lesions are based on light-microscopic examination of H&E-stained thin-slice specimens. Recently, a concept of optical biopsy has been advocated. A study of the observation of colorectal lesions using endocytoscopy to obtain real-time histological images in vivo during endoscopy was performed. Full-Text PDF Response:Gastrointestinal EndoscopyVol. 64Issue 6PreviewWe appreciate the comments of Fu et al regarding our article1 and would like to respond to their questions. We stated in our article that the endocytoscopy system is superior to the current magnifying endoscopy in the sense that, with the endocytoscopy technique, we could evaluate both structural and cellular atypia in vivo. We did not need to refer to the results of pit pattern diagnosis in comparison to endocytoscopy because we did not perform a double-blinded study, and such comparison was not the aim in our study. Full-Text PDF