大腸の大きな腺腫（3cm以上，villous tumor，結節集簇様病変を含む）の取り扱いと経過・予後―外科の立場から

Clinical Management and Prognosis of Large Adenomas of the Colorectum

要旨　過去13年間に経験した3cm以上の大腸腺腫24例の臨床病理学的特徴と治療について検討した．部位別では下部直腸，S状結腸，右側結腸の順に多く，villous tumorと結節集簇様病変で全体の75％を占めていた．組織型は腺管絨毛腺腫が13例(54％)と多く，異型度は腺腫内癌が14例(58％)と一番多かった．Is，Isp，Ip型は内視鏡的ポリペクトミーで対処でき，再発例はなかったが，villous tumorないし結節集簇様病変の多くには局所切除ないし腸切除を要した．内視鏡的ポリペクトミーないし局所切除を受けた6例に再再発がみられたが，全例局所切除ないし内視鏡的ポリペクトミーで対処可能であった．

　Twenty-four large adenomas of the colorectum, over 3 cm in diameter, were collected from the endoscopy and surgery files of The First Dept. of Surgery, The University of Tokyo, and their clinicopathological details and treatment modalitities were reviewed. Among 24 lesions, 11(46%) were located in the rectum, 6 (25%) in the sigmoid colon and 5 (22%) in the right colon, respectively. Gross appearances were divided into villous tumor in 12 lesions (50%), nodule-aggregating lesion in 6 lesions (25%)and polypoid lesion (Is, Isp, Ip) in 6 lesions (25%), respectively. Histology showed tubular adenoma in 8 lesions (33%), tubulo-villous adenoma in 13 lesions (54%) and villo-tubular adenoma in 3 lesions (13%), respectively. Grades of atypia were classified into Ca in adenoma in 14 lesions (58%), moderate atypia in 7 lesions (29%)and mild atypid in 2 lesions (8%), respectively. All polypoid lesions were able to be resected with endoscopic polypectomy alone and no tumor recurrence was found. However, surgical treatment (local excision or bowel resection) was mandatory for most of the villous tumors and nodule-aggregating lesions. Six of 13 tumors (villous tumor or nodule-aggregating tumor) recurred between two month and 10 years after initial treatment. All recurrent tumors were histologically benign and could be treated with endoscopic polypectomy or local excision. Re-recurrence was observed in two villous tumors, however, endoscopic polypectomy was appropriate to treat these tumors. The importance of endoscopic surveillance was stressed.