title: Sub-classification of type VI pit patterns in colorectal tumors: relation to the depth of tumor invasion.
abstract: We analyzed pit patterns of colorectal tumors with magnifying colonoscopy, focusing on the relationship between the VI pattern sub-classification and the depth of tumor invasion. The VI pattern was divided into the well-demarcated and poorly demarcated subtypes. The percentage of tumors with a depth of invasion of over 1,000 microm was in the order of non-V types (type I-IV) < type VI < type VN. Most well-demarcated VI lesions (80.8%) showed a depth of invasion of <1,000 microm compared to only 21.1% of poorly demarcated VI lesions. Both the frequency of degeneration or prolapse of the epithelial lining and the frequency of desmoplastic reaction occurred in the order of non-V types < type VI < type VN, while the degree of histological differentiation and the frequency of residual muscularis mucosae occurred in the order of non-V types > type VI > type VN. Furthermore, the poorly demarcated VI subtype showed a higher frequency of epithelial lining degeneration or prolapse and a lower frequency of residual muscularis mucosae than the well-demarcated VI subtype. Tumors with a depth of invasion of >1,000 microm showed a higher frequency of epithelial lining degeneration or prolapse, a lower degree of histological differentiation, a higher frequency of desmoplastic reaction, and a lower frequency of residual muscularis mucosae than did tumors with <1,000 microm of invasion. These results suggest that VI pit pattern sub-classification is a useful indicator of the depth of colorectal tumor invasion and treatment selection. A prospective study on this subject would be useful.
authors.affiliation: Division of Gastroenterology, Department of Medicine, Kurume University School of Medicine, Kurume 830-0011, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Tobaru
authors.forename: Keiichi
authors.initials: K
authors.lastname: Mitsuyama
authors.forename: Osamu
authors.initials: O
authors.lastname: Tsuruta
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kawano
authors.forename: Michio
authors.initials: M
authors.lastname: Sata
mesh_terms: D000230:Adenocarcinoma / Q000145:classification* / Q000473:pathology*; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000145:classification* / Q000473:pathology*; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology