Colorectal Cancer
Copyright ©2008The WJG Press and Baishideng. All rights reserved.
World J Gastroenterol. Jan 14, 2008; 14(2): 211-217
Published online Jan 14, 2008. doi: 10.3748/wjg.14.211
Clinical significance of type VI pit pattern subclassification in determining the depth of invasion of colorectal neoplasms
Hiroyuki Kanao, Shinji Tanaka, Shiro Oka, Iwao Kaneko, Shigeto Yoshida, Koji Arihiro, Masaharu Yoshihara, Kazuaki Chayama
Hiroyuki Kanao, Iwao Kaneko, Kazuaki Chayama, Department of Medicine and Molecular Science, Hiroshima University Graduate School of Biomedical Science, Hiroshima, Japan
Shinji Tanaka, Shiro Oka, Shigeto Yoshida, Department of Endoscopy, Hiroshima University Hospital, Hiroshima, Japan
Koji Arihiro, Department of Pathology, Hiroshima University Hospital, Hiroshima, Japan
Masaharu Yoshihara, Health Service Center, Hiroshima University, Hiroshima, Japan
Correspondence to: Shinji Tanaka, MD, PhD, Department of Endoscopy, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan. colon@hiroshima-u.ac.jp
Telephone: +81-82-2575538
Fax: +81-82-2575538
Received: August 20, 2007
Revised: September 29, 2007
Published online: January 14, 2008
Abstract

AIM: To clarify whether subclassification of the type VI pit pattern on the basis of magnifying colonoscopy findings is useful in determining the type and depth of invasion of colorectal neoplasms.

METHODS: We retrospectively analyzed 272 colorectal neoplasms (117 dysplasias and 155 submucosal invasive carcinomas; 228 patients) with a type V pit pattern [type VI, n = 202; type VN, n = 70 (Kudo and Tsuruta classification system)]. We divided lesions with a type VI pit pattern into two subclasses, mildly irregular lesions and severely irregular lesions, according to the prominent and detailed magnifying colonoscopy findings. We examined the relation between these two subclasses and histology/invasion depth.

RESULTS: One hundred and four lesions (51.5%) were judged to be mildly irregular, and 98 lesions (48.5%) were judged to be severely irregular. Ninety-seven (93.3%) mildly irregular lesions showed dysplasias or submucosal invasion of less than 1000 &mgr;m (SM < 1000 &mgr;m). Fifty-five (56.1%) severely irregular lesions showed submucosal invasion equal to or deeper than 1000 &mgr;m (SM ≥ 1000 &mgr;m). Mild irregularity was found significantly more often in dysplasias or lesions with SM < 1000 &mgr;m than in lesions with SM ≥ 1000 &mgr;m (P < 0.01).

CONCLUSION: Subclassification of the type VI pit pattern is useful for identifying dysplasias or lesions with SM < 1000 &mgr;m.

Keywords: Colorectal neoplasm, Magnification, Type VI pit pattern, Depth of invasion