腹腔鏡下切除を施行した上行結腸神経鞘腫の1例

Laparoscopic resection of schwannoma of the ascending colon : a case report

◆要旨：腹腔鏡下切除を施行した上行結腸神経鞘腫の1例を経験した．患者は58歳，男性．右側腹部痛を主訴に当院を受診した．精査の結果，胆石と上行結腸に45mm大の粘膜下腫瘍を認めた．生検では確定診断が得られず，間葉系腫瘍，特にgastrointestinal stromal tumor（GIST）を疑って手術を施行した．腹腔鏡下観察では，腫瘍は硬くて被膜もしっかりしており，周囲臓器への浸潤所見はなかったため，腹腔鏡下結腸右半切除術・胆囊摘出術を施行した．病理組織検査にて良性神経鞘腫と診断した．大腸神経鞘腫は術前に確定診断を得られないことが多いが，間葉系腫瘍を疑った場合，術中所見から慎重に術式を選択することで腹腔鏡下切除の適応となる症例が増える可能性があると考えられた．

　Schwannomas of the colon and rectum are uncommon and the indication for laparoscopic resection is not clear. We report a case of schwannoma in the ascending colon which was successfully resected by laparoscopic surgery. A 58-year-old man visited our hospital with a chief complaint of right upper abdominal pain. Gallbladder stones and a tumor, which is 45 mm in diameter, of the ascending colon were detected by ultrasonography and computed tomography. Biopsy specimens of the submcosal tumor could not be obtained under colonoscopic examination. The operation was performed with the preoperative diagnosis of mesenchymal tumor of the ascending colon. In the laparoscopic examination, the capsule of the hard tumor was strong, and the findings of tumor invasion to the surrounding organs were not detected. Laparoscopic right hemicolectomy and colecystectomy were performed. The tumor was diagnosed as benign schwannoma by histopathological and immunohistochemical examination. The diagnosis of colorectal schwannoma is rarely confirmed preoperatively. The laparoscopic findings are helpful in the decision of indication for laparoscopic resection of colorectal mesenchymal tumors, even in a case of schwannoma.