大腸腫瘍のミクロとマクロの対比における新しい知見―pit patternのフラクタル解析と組織所見との対比

Fractal Analysis of Pit Patterns and Histologies: A Novel Finding for Correlation between Macroscopic and Microscopic Features of Colorectal Neoplasias

要旨　大腸粘膜内上皮性腫瘍55病変（腺腫37例，低異型度癌7例，高異型度癌11例）を対象に，病変のpit patternとそれに対応する組織腺管構造のフラクタル解析を行い，両者のフラクタル次元の相関について定量的検討を行った．円形，類円形，管状，樹枝状の4型に分類されたpit patternのフラクタル次元は1.06，1.27，1.39，1.57であり，より複雑なパターンほど高いフラクタル次元が得られ，それぞれの間で有意差を認めた．pit patternと対応する組織腺管構造のフラクタル次元には有意な相関関係があり，pit patternは病理組織診断における構造異型を反映していることが定量的にも示された．腺腫と低異型度癌との間には，pit pattern，組織腺管構造ともにフラクタル次元に有意差がみられた．低異型度癌と高異型度癌との比較では，組織腺管構造のフラクタル次元が両者で近似していた（1.49 vs. 1.51，p=0.72）のに対し，pit patternのフラクタル次元は高異型度癌で高い値を示す傾向があり（1.55 vs. 1.61，p=0.15），pit patternは構造異型のほかに細胞異型も反映している可能性が示唆された．

　The fractal dimensions of pit patterns (shapes and the arrangement arranging pattern of the orfice of the crypts) and their corresponding histology (tubular structure) by H･E sections were analysed and compared in 55 colonic intramucosal epithelial neoplasias (37 adenomas, seven carcinomas with low-grade atypia and 11 carcinomas with high-grade atypia) . The pit patterns were classified into round, roundish, tubular and branching and their average fractal dimensions were 1.06, 1.27, 1.39, 1.57, respectively. The more complex and irregular the pit patterns were the higher the fractal dimensions. Positive correlation was found between the fractal dimension of the pit pattern and the corresponding histology, indicating that pit patterns quantitatively reflect the structural atypia of the tumor. There was a significant difference in both pit pattern and histology and also in fractal dimension according to whether the lesions were adenoma or carcinoma (both low-grade and high-grade). The difference in the fractal dimensions of low-grade and high-grade carcinomas was not significant either histologically (1.49 vs. 1.51, p=0.72), or by the pit pattern trends (1.55 vs. 1.61, p=0.15). These data imply that pit pattern may reflect not only the structural atypia but also the cellular atypia of colonic intramucosal epithelial neoplasia.