10mm以下の大腸隆起型（無茎性，亜有茎性）腺腫の経過観察例の検討

Follow-up Study of Sessile and Subpedunculated Type Colorectal Adenomas Less Than 10 mm in Diameter

要旨　初回内視鏡検査での生検にて腺腫と診断された，10mm以下の無茎性，亜有茎性の隆起型大腸腺腫（以下，大腸隆起型腺腫と略す）99例105病変について，2年～10年1か月（平均4年1か月）の経過観察を行い，以下のような結果を得た．①10mm以下の大腸隆起型（半球状）腺腫について，平均観察期間4年1か月では形態変化を伴う著しい増大は認めず，増大病変のほとんどは軽度（2～3mm）の増大であった．②10mm以下の大腸隆起型腺腫に対する積極的なポリペクトミーは，大腸癌を減少させるためにさほど有効に作用していないだろうと推定された．③腺腫か癌かの生検による病理診断が十分に確立していない現状では，10mm以下の大腸隆起型腺腫に対する処置は，一定期間経過観察を行い，大きさや形態の変化を認めた時点でポリペクトミーなどを考慮してもよいのではないかと考える．

　We analyzed 99 followed-up cases,105 lesions, of protruded (sessile and/or subpedunculated) type colorectal adenomas less than 10 mm in diameter, all of which were diagnosed as adenoma from biopsy specimen at the initial endoscopic examination. The result were as follows:

　(1) The lesions did not showed marked change in size and shape during the observation period (four years and one month in average). In most of the enlarged cases, the growth of lesion was limited within 2 to 3 mm.

　(2) As histological diagnosis between adenoma and carcinoma has not definitely established yet, protruded type colorectal adenomas measuring less than 10 mm should be followed up for some period, and treatment including polypectomy should be considered when they show dimensional or morphological change.

　(3) From the result of this study, we assume decrease of colorectal carcinomas could not be much expected through increase of polypectomy for those type adenomas.