大腸腫瘍の分布に関する検討

A Study on the Distribution of Colorectal Tumors

要旨　total colonoscopyの症例により大腸腫瘍（腺腫・早期癌）の分布を検討した．591人に1,075個の腫瘍が発見され，そのうち腺腫は82％を占めた．5mm以下の小腫瘍は広基性腺腫が圧倒的に多いので主として6～20mmの腫瘍について検討した．部位と形態の相関については腺腫でも癌でも似た傾向がみられた．平均値に比べて直腸では扁平腫瘍と広基性腫瘍が多いが，その中では扁平腫瘍で癌が多く腺腫はむしろ少なかった．右側結腸では扁平腫瘍が多く，癌と腺腫に差はみられなかった．total colonoscopy例以外のものも含めた早期癌についてみると，直腸と右結腸にはくびれのない腫瘍（扁平・広基）が多く，左結腸ではくびれのある腫瘍（有茎群）が84％と圧倒的に多かった．m癌とsm癌を比べると扁平腫瘍がsm癌で部位を問わず多く，特に直腸と右結腸でその傾向が強かった．扁平腫瘍が診断されるようになってきたが，まだ発見されるものは一部に限られているようにみえる．そういったコロノスコピーの弱点を克服するのに最近普及してきた電子スコープおよびカラーコレクターなどの偽カラー法を用いた方法が期待される．

　The distribution of colorectal tumors was investigated using the data obtained by total colonoscopy. One thousand and seventy five tumors (adenoma, early cancer) were observed among 591 patients. Eighty two percent of them were benign adenoma. Diminutive tumors were mostly adenomas, sessile in shape. Therefore, tumors of 6 mm or more in size were studied. Flat and sessile tumors were found more at the rectum compared to the left side colon. Flat tumors of the rectum were malignant more than average.

　Flat tumors were also popular in the right side colon. However, malignancy rate was not so high as in the rectum.

　Early cancers were studied using the data obtained not only by total colonoscopy but by partial examination.

　Early cancers without stalk (flat, sessile) were prevailing in the left side colon. Although often lumped under one name of early cancer, m and sm cancers differ considerably in shape. The ratio of flat tumors are higher among sm cancers than among m cancers both as a whole and in each individual segment.

　Although more and more flat tumors have come to be diagnosed, there are not a few evidences that they still are missed during colonoscopy. To overcome the faults of colonoscopy, the newly introduced electronic colonoscopes are much to be expected.