純粋Ⅱb型早期胃癌の病理

Pathological Study on Pure Ⅱb Type Carcinoma of the Stomach

要旨　“癌巣の粘膜面全体が癌巣周囲の正常粘膜面とほぼ同じ高さを示している早期胃癌”と定義された純粋Ⅱb型早期胃癌10個（微小癌を除く）を用いて，本癌の成り立ちと肉眼所見の形成を検討した．この際，癌組織の粘膜内進展様式を，腺窩層間質型，腺窩層全層型，粘膜全層型に分類することが有用であった．その結果，本癌は，①癌組織型別に固有の粘膜内進展の特性，②粘膜内での癌組織の量，③粘膜の腸上皮化生，固有胃腺の萎縮，線維筋症の程度，④胃酸の消化作用，などの総合因子で規定された癌巣粘膜の厚さと周囲粘膜の厚さとが，同じ高さの均衡を保つ場合に形成される肉眼形態であると考えられた．更に，本症癌巣の表面模様の形成には癌巣深部の線維筋症と固有胃腺の多寡が，色調の変化には癌組織の露呈と癌組織内の拡張した毛細血管の増加が大きく関与していると考えられた．

　Ten pure Ⅱb type carcinomas of the stomach were histologically exanlined to determine the factors involved in the development of their gross appearances. Three types of intramucosal extension of the carcinoma were found:stromal foveolar type; total foveolar type; total mucosal type. This classification was useful in identifying the determinants of the pure Ⅱb type carcinomas of the stomach. These are histology of carcinoma, amount of tumor tissue in the lamina propria mucosae, degree of intestinal metaplasia, glandular atrophy and fibromusculosis, and peptic effect of gastric juice.

　The gastric area-like appearance of the cancer lesions varied depending on the volume of fibromusculosis and tumor tissue, while their color was related to the amount of congested capillaries in the tumor tissue.

　These characteristics in mucosal appearance and color were sensitive enough in macroscopically detecting pure Ⅱb type carcinomas in seven out of ten patients.