大腸カルチノイド腫瘍の外科治療

Surgical Treatment for Colorectal Carcinoid Tumors

要旨　転移陽性カルチノイドの特徴について検討し，大腸カルチノイドの外科的な治療方針を作成した．大きさ10mm以下の病変では内視鏡的摘除術や局所切除術の適応である．組織学的検索を行い，smまでの浸潤であること，核分裂像や脈管侵襲がないことを確認する．これらが満たされていない場合はリンパ節郭清を併用した根治手術を考慮する．大きさ10～20mmの病変は，結腸やRs，Raであれば腹腔鏡（補助）下手術を行う．病変がRbや肛門管に位置する場合，局所切除で経過観察とするか根治術（人工肛門作製）を行うかの選択は慎重に判断する．大きさが20mm以上の病変やmp以深に浸潤したカルチノイドに対しては，根治術を行う．カルチノイドには癌との合併が多いとされ，特に大腸癌，胃癌の精査は治療前に行う．

　We studied the characteristics of colorectal carcinoid tumors with metastasis, and made a protocol of surgical treatment for colorectal carcinoid tumors. If the size of the lesion is under 10 mm, endoscopic mucosal resection or local excision is appropriate. The resected specimen is to be investigated histopathologically, and it should be confirmed that the lesion is limited to the submucosal layer and that it shows no mitosis and no vasculolymphatic permeation. Radical treatment would be considered if it invades the muscularis propriae, or when mitosis or vasculolymphatic permeation is observed by microscopy. If it is from 10 to 20 mm and if it is located in the colon, Rs or Ra, laparoscopic surgery is appropriate. But if it is at Rb or the anal canal, the choice should be made deliberately whether local resection is sufficient, or whether a radical operation with creation of a permanent colostomy would be carried out. If the size is greater than 20 mm, or if it invades the muscularis propriae, a radical operation is needed. Because of the increased risk of synchronous cancers, patients with carcinoid tumors should undergo appropriate screening and surveillance especially for colorectal and gastric cancers.