表面型大腸腫瘍の内視鏡的切除後の経過観察に関する検討

Follow-up Examination of Superficial Type Colorectal Tumors after Endoscopic Resection

要旨　表面型大腸腫瘍の内視鏡治療後の経過を検討した．対象は当院で内視鏡検査を4回以上受け，初回検査時に表面型腫瘍を内視鏡治療された145症例である．その結果，検査回数を重ねると腫瘍発見治療率は減少し，Ⅱa＋Ⅱc，平坦・陥凹型腫瘍，creping tumorはその割合は少ないが検査ごとに発見・治療された．早期癌は，隆起型では検査3回目までに治療されていたが，表面型およびcreeping tumorでは検査回数を重ねても発見・治療された．陥凹型は他の形態と異なり，検査4回目までsm癌が認められた．内視鏡治療後の経過観察の留意点は，検査回数とは関係なく表面型腫瘍，その中でも陥凹型癌を念頭に置き，注意深い観察を行うことである．

　We retrospectively examined the course of superficial type colorectal tumors after endoscopic resection. Subjects of the study were 145 cases of superficial type colorectal tumors (Ⅱa, Ⅱb, Ⅱc, Ⅱc+Ⅱa, Ⅱa+Ⅱc), protruded type tumors (Ip, Ips, Is) and creeping tumors, which had been observed by follow-up colonoscopy in our hospital over four times after endoscopic resection on the first colonoscopy.

　The result showed basically that the more colonoscopy were repeated, the fewer the number of detected tumors became. However, in spite of decrease of the rate of detection, flat and depressed type (Ⅱb, Ⅱc, Ⅱc+Ⅱa), Ⅱa+Ⅱc type and creeping type cancers were detected and resected on each follow-up colonoscopy. Although protruded type cancers disappeared after the third colonoscopy, superficial type and creeping type cancers were detected and resected even after the fourth colonoscopy. Depressed type cancers were unique in that other depressed type cancers which invaded the submucosal layer were found even on the fourth follow-up colonoscopy.

　This fact shows that careful observation on each colonoscopy is necessary to prevent overlooking the superficial type tumors, especially depressed type cancers, however often it is repeated.