壁外性発育が主体であった直腸カルチノイド腫瘍の1例

Carcinoid Tumor of the Rectum with Extramural Giant Growth, Report of a Case

要旨　患者は64歳，女性．既往に痔瘻手術歴があり，肛門痛を主訴に来院．精査の結果Rb後壁に巨大な粘膜下腫瘍様充実性病変を認めたが，組織学的には針生検で中分化腺癌が疑われた．切除標本の組織像よりchromogranin A染色が陽性で，筋層以深の壁外性発育を主体とするカルチノイド腫瘍と診断された．腫瘍近傍に重複腸管と思われる構造が存在し，そこから連続する瘻管が腫瘍の中央を貫通しており，カルチノイド腫瘍発生への関与が示唆された．

　A 64-year-old Japanese woman was admitted to our hospital with the complaint of anal pain. She had undergone an operation for anal fistula 25 years before. Further radiographic examinations revealed a submucosal tumor-like giant elevated solid mass in the posterior wall of the lower rectum. Abdominoperineal resection of the rectum was performed, and the tumor was histologically diagnosed as a rectal carcinoid with extramural giant growth. Furthermore a fistula, connecting with a small rectal duplication, had penetrated the tumor and the walls of the fistula were strongly positive for chromogranin A stain. So it is suggested that the tumor may have originated from the rectal duplication.

　1) Department of Coloproctology, Social Health Insurance General Hospital, Tokyo