10mm以下のsm深部浸潤癌の病理学的特徴―組織学的な計測に基づいて

The Characteristic Features of Small Submucosal Massive Invasive Colon Cancer

要旨　長径1cm以下の粘膜下深部浸潤癌の臨床病理学的な特徴を検討するために，171例の粘膜下浸潤癌(sm癌)を，微小浸潤癌14例(sm浸潤長1mm以下)，長径1cm以下のsm深部浸潤癌20例(sm浸潤長1mmより大)および長径1cmより大なるsm深部浸潤癌137例に分けて検討した．1cm以下のsm深部浸潤癌の特徴は，non-polypoid growthの増殖様式を示す癌が多いことや主組織の細胞異型の高い癌が多いために，早期に深部浸潤を来した傾向があることである．さらに，浸潤性の増殖を示し，先進部でsprouting陽性を示す癌が多いことなどにより，リンパ管侵襲やリンパ節転移の率が高い傾向があった．以上より，1cm以下のsm深部浸潤癌は，sm微小浸潤癌や1cm以上のsm深部浸潤癌に比べて，悪性度が高い癌であると結論した．

　One hundred and seventy one cases of submucosal invasive colon cancers were studied to discover the characteristic features of submucosal massive invasive carcinoma under 1 cm in diameter.

　Submucosal invasive cancers were divided into 3 groups, “A” group was made up of sm-minimum invasive cancers (14 cases) in which submucosal invasion was 1 mm or less in depth, “B” group was sm-massive invasive cancer (20 cases) in which submucosal invasion depth was over 1 mm and tumor diameter was 1 cm or less, and “C” group was submucosal invasion over 1 mm in depth and whose tumor diameter was over 1 cm.

　The characteristic features of “B” group were the rate of non-polypoid cases in growth pattern, the rate of histological cell atypia of the main tumor showing high-grade malignancy, the rate of tumor which showed front-sprouting pattern, and the rate of lymphnode metastasis and lymphatic permeation were higher than the rates found in other types.

　Result: The submucosal massive-invasive cancer under 1 cm in diameter had high-grade malignancy, the tumor invaded in the early stage and the metastatic rate was high.