大腸腺腫および癌の病理形態学的研究―構造異型のmorphometricな分析による良性・悪性の鑑別について

Morphometric Analysis of Structural Atypism of Adenoma and Carcinoma of the Large Intestine with Special Reference to Borderline Lesion between Benignancy and Malignancy

　病理組織学的な腫瘍の良性・悪性の診断は，細胞水準での細胞異型と組織水準での構造異型との総合的判断によって行われている．

　異型とは“正常からの形態的なかけ離れ”を意味するものであるから，われわれが病理組織学的に腫瘍の良性・悪性の診断をするということは，ある正常のパターンからのかけ離れの程度を経験的あるいは直観的に認識して，良性あるいは悪性に類別するという手続きを行うことである．しかし，本来異型の程度というものは連続的であるので，実際には良性・悪性境界領域という判断の難しい異型が生じてくる．腫瘍の病理組織診断においては，客観的にこの良性・悪性境界領域の幅を狭めることが常に要請されている．

　The purpose of the present paper is to analyz morphornetrically the structural atypism of benign adenomas and carcinomas of the large intestine, that is to say two-dimensionally and three-dimensionally, and to divide the borderline lesions into benign adenomas and carcinomas from the view-point of structural atypism.

　One hundred and forty-nine polyps with atypism of the large intentine were classified into 63 benign adenomas, 30 carcinomas and 31 borderline lesions from the view-point of their cellular atypism (Table 1).

　1) Two-dimensional analysis of structural atypism (Table 2): The average of index of structural atypism (I.S.A. = area of glands per unit area/area of the stroma per unit area) was as follows; carcinoma 5.41±1.61, benign adenoma 2.76±0.93 (Fig. 5, Table 5). I.S.A. of benign adenomas showed a normal distribution but that of carcinomas did not. I.S.A. of borderline lesions was 5.44±1.08 and was included within the range of I.S.A.of carcinomas.

　2) Three-dimensional analysis of structural atypism: Anastomosis between two glands and/or loop in a gland are observed in adenomas and carcinomas of the large intestine by means of reconstruction of specimens serially sectioned (Fig. 1 and 8). Furthermore, there are the branchings of glands in them. These can be identified as the structural atypism of three dimensions, because the norma1 mucosa of the large intestine consists of non-branched tubules.

　a) The average number of branching of a gland of carcinoma was 2.2 times more than that of benign adenoma. That of borderline lesion was 1.3 times more than that of benign adenoma (Table 6).

　b) Applying topological homotopy, Betti number of one dimension (P₁=no.of anastomosis + no.of loop) of the glands of carcinomas was 2.2 times more than that of benign adenomas. That of borderline lesions was 1.1 times more than that of benign adenomas (Table 7).

　c) The structural atypism of three dimensions could be expressed topologically as minus Euler's characteristics (-K) in a plane (Fig. 2). Frequency of -K glands per unit area of carcinoma was three times higher than that of benign adenoma. That of borderline lesion was included within the range of that of carcinoma (Table 8).

　3) Twenty-six borderline lesions were divided into carcinomas and benign adenomas by comparing I.S.A. and frequency of -K glands with those of carcinomas and benign adenomas. The obtained results were as follows; two were benign, four were malignant, but the remaining 20 lesions (77%) could not be determined, that is, so-called “borderline”from the viewpoint of both cellular and structural atypism (Table 10).