病変表層の組織構築からみたsm massive癌の診断―pit patternとSA patternを中心に

Impact of Two Magnifying Chromocolonoscopic Findings on Detecting Invasive Colorectal Cancer―Pit Pattern and SA Pattern, using Crystal Violet Staining

要旨　深達度の面からは単純に一括されているsm masssive癌も，その表層組織構築は多様である．この多様性を拡大内視鏡である程度判別できれば，よりきめの細かい深達度診断が可能になると考えられる．このような経緯から，sm masssive癌の診断指標を明らかにする目的で，pit pattern・SA patternの両拡大内視鏡所見と，sm massive癌の表層組織構築との関係を検討した．フラクタル解析で数値化したpit patternの複雑さはsm massive癌の表層剥離の程度が進んだ病変ほど高値を呈したが，これは表層剥離の進んだ病変に高異型度癌が高頻度に存在することに依存していると考えられた．一方，SA patternは粘膜内部のみならず被覆上皮の残存程度を反映し，sm浸潤度を反映していた．

　It is sometimes difficult to identify colorectal cancers invading down to the submucosa by magnifying chromocolonoscopic examination, especially in cases of lesions with numerous pits on their surface. One of the reasons for this difficulty lies in the fact that little is known about detailed magnifying chromocolonoscopic findings of these lesions despite their numerous patterns of superficial histologic constructions. Therefore, the co-relation between these endoscopic findings and superficial histologic construction of the equivalent area were investigated in order to clarify a method for identifying these lesions correctly. In the present study we employ two chromocolonoscopic findings, pit pattern and SA pattern, the staining patterns of the area between pits. Complexities of pit patterns were evaluated by means of fractal dimensions using the box-counting method. SA patterns were classified into three types, type A, B, and C, according to their density under staining. Close co-relation was found between SA pattern and histologic construction. However, little co-relation was found between pit patterns and the histologic construction although close correlation was found between pit pattern and, histologic glandular and celluar atypia. It would be of great practical advantage to have a knowledge of SA pattern for detecting cancers invading down to the submucosal layer.

　1) Department of Gastroenterology, Shun-ichi Hayashi Clinic, Mitsuke, Japan

　2) Division of Molecular and Functional Pathology, Department of Cellular Function, Graduate School of Medical and Dental Sciences, Course of Molecular and Cellular Medicine, Niigata University, Niigata, Japan