回盲弁lipohyperplasiaを合併した回腸末端部カルチノイドの1例

Carcinoid Tumor in the Terminal Ileum with Lipohyperplasia of the Ileocecal Valve, Report of a Case

要旨　患者は56歳，男性．血便を主訴として，近医を受診した．経口小腸造影で回盲部の異常を指摘され，当院に紹介された．注腸X線検査で，回盲弁の著明な腫大と同弁に隣接した回腸末端部に，径2cm大の腫瘤を認めた．大腸内視鏡では，腫大した回盲弁口から突出した発赤を伴う不整な隆起性病変を認め，生検の結果，カルチノイド腫瘍と診断された．病理組織学的には，粘膜下層を主座とする充実胞巣状の腫瘍細胞の増殖から成り，固有筋層まで達し，1群リンパ節転移も認めた．また腫大した回盲弁は粘膜下に過剰に増生した成熟脂肪組織から成り，lipohyperplasiaと診断した．

　A 56-year-old male presented himself at our hospital with a complaint of bloody stool. This was after a deformity in the ileocecal region had been detected by a barium study of the small intestine at another clinic. A barium enema study showed both an enlargement of the ileocecal valve and a tumor measuring 2.2 cm in diameter in the terminal ileum. Colonoscopy revealed an irregularly elevated lesion with a reddish surface, and biopsy specimens from the tumor indicated a carcinoid tumor. Histopathologically, the tumor was located in the submucosal layer, while it had also partly invaded the muscularis propria. In addition, metastasis was also observed in the regional lymph nodes. The tumor cells proliferated in a cribriform pattern. The enlargement of the ileocecal valve consisted of over-proliferative mature fatty tissue and was diagnosed to be lipohyperplasia.