S状結腸癌を合併した大腸子宮内膜症の1例

Adenocarcinoma of the Sigmoid Colon Arising in Endometriosis, Report of a Case

要旨　大腸子宮内膜症にS状結腸癌を合併した極めてまれな症例を経験した．患者は52歳，女性で，以前に骨盤子宮内膜症で子宮全摘，両側卵巣切除を受け，S状結腸子宮内膜症を指摘されている．便潜血陽性，腹痛のため精査を受けたところ，S状結腸の著しい狭窄を指摘され手術を受けた．病理組織学的所見では，S状結腸子宮内膜症に共存する高～中分化腺癌の浸潤がみられ，組織像，浸潤様式からS状結腸予宮内膜症の癌化ではなく，S状結腸癌の合併と診断した．

　A very rare case of sigmoid colon cancer arising in endometriosis is presented. A 52-year-old female patient who had undergone bilateral salpingo-oophorectomy with hysterectomy for endometriosis at 46 years of age was admitted to our hospital due to lower abdominal pain. Barium enema study revealed obstruction in the sigmoid colon. Anterior resection of the recto-sigmoid colon was performed.

　A firm tumor with dense induration on the outer wall and ulceration on the inner lumen was observed in the resected specimen. Histopathological examination showed ectopic endometrial glands and tubular adenocarcinoma with subserosal invasion. The histological similarity with common colorectal cancer and the absence of direct continuity with endometrial glands supported the diagnosis of sigmoid colon cancer arising in endometriosis.