10mm未満の早期大腸癌のX線・内視鏡的特徴―実体顕微鏡所見を含めて

Radiologic and Endoscopic Characteristics of Colon Cancers Smaller than 10 mm, Dissecting Microscopic Results Contrasted

要旨　臨床で発見された10mm未満の大腸癌は，大腸癌の13.1％を占め，すべて早期癌であった．sm癌が4例あるが，5mm未満にはみられなかった．それらの形態は，平板状隆起が42.3％を占め，sm癌では75％が平盤状隆起であった．実体顕微鏡で発見されたものは，平盤状隆起または平坦型が85.7％を占め，臨床で見逃されている可能性が大きい．実体顕微鏡で発見されたものは，臨床で発見されたものに比べ腺腫を伴わないものが多かった．5mm内外の小さな大腸癌は，生検により病変消失，生検陰性になることがあるが，初回の生検所見で腺種を伴っていないものが多かった．

　Colorectal cancers smaller than 10 mm were clinically detected by 13.1％, all of them being early. Four cases reached the sm layer, all being in the excess of 5 mm. Those cancers smaller than 10 mm showed flat-topped elevation or plateau by 42.3％ while sm cancers by 75.6％.

　Those lesions detected through dessecting microscope were more likely to show either flat-topped elevation or no neveau difference. Therefore they were estimated to be overlooked not infrequently on a clinical level.

　Colorectal cancer smaller than 5 mm and more or less could disappear by biopsy resulting in subsequent negative biopsy. Initial biopsy showed no accompanying adenoma for the most part.