多発肝転移を伴った最大径1cmの直腸カルチノイド腫瘍の1例

Rectal Carcinoid Tumor 10 mm in Diameter Accompanied by Multiple Liver Metastases, Report of a Case

要旨　症例は58歳，女性．便秘を主訴に近医を受診し，S状結腸内視鏡検査で直腸に隆起性病変を指摘され当院に紹介となった．注腸X線検査で直腸に表面に小陥凹を伴う1cm大の粘膜下腫瘍を認めた．大腸内視鏡検査で，同病変は表面平滑で黄色調を呈する粘膜下腫瘍であった．内視鏡的粘膜切除術を施行し，病理学的に深達度smの古典的カルチノイドと診断された．また，腹部超音波検査で肝S3に1cm大の低エコー域を，S5に1cm大の高エコー域を認めた．肝嚢胞および肝血管腫を疑い経過観察していたが，約3年後に肝結節は増大，増加したため外科的切除を施行した．病理学的にカルチノイドと診断され，直腸カルチノイドの多発肝転移と考えられた．

　A 58-year-old woman was referred to our hospital, because of a polypoid lesion in the rectum. Radiography and colonosopy revealed the lesion to be a semispherical, smooth tumor with a shallow depression, measuring 10 mm in diameter. The tumor was removed using the endoscopic mucosal resection technique. Histologicl examination of the resected tumor revealed the lesion to be a classical cacinoid tumor restricted to the submucosal layer. At that time, the patient was diagnosed by ultrasonography as having two liver nodules in the liver. Because the hepatic nodules increased in size and number during the subsequent three years, they were resected by surgery. Histologically, the hepatic nodules were composed of carcinoid cells . Although classical carcinoid of the rectum is presumed to have low malignant potential, our case suggests that careful considerations as regards the choice of therapy and intensive follow-up are deemed necessary in cases of rectal carcinoid tumors.