潰瘍性大腸炎以外の炎症性腸疾患と腫瘍―その臨床病理組織学的特徴

Clon Cancer Accompanied by Inflammatory Bowel Diseases (IBD): The Clinicopathological Features

要旨　炎症性腸疾患と大腸癌の臨床病理学的特徴について，主として本邦文献を渉猟して検討した．放射線腸炎および大腸結核合併大腸癌は通常大腸癌と比較し年齢差を認めなかった．Crohn病および潰瘍性大腸炎合併大腸癌は明らかに若年に認められた．これらの4疾患に合併した大腸癌の肉眼型では，通常大腸癌にみられる2型の頻度は著しく少なかった．また組織型は通常まれな粘液癌を高頻度に認めた．それらの原因としては，これらのいずれの炎症性腸疾患も，粘膜下層に線維化がみられ，粘膜下層に腫瘤を形成できないこと，線維化によって，管腔内に粘液が排泄できないことが考えられた．炎症性腸疾患と大腸癌の合併は，炎症の好発部位に発生する頻度が高いことから偶然ではないと考えられた．

　On a survey of the Japanese literature, the clinicopathological relationship between colon cancer and IBD was investigated.

　(1) A combination of colon cancer and IBD does not exist by mere chance, because colon cancer has occurred within the existsing IBD in most cases.

　(2) The average age of patients with colon cancer accompanied by Crohn's disease and ulcerative colitis was younger than that of patients with colon cancer without IBD.

　(3) In colon cancer accompanied by intestinal tuberculosis, the females outnumbered the males with a ratio of 7: 3.

　(4) Macroscopically, there was a significantly small number of colon cancers accompanied by IBD of type 2. Microscopically, mucinous carcinoma, which is rare in ordinary colon cancer, was frequent in colon cancer accompanied by IBD. Such macroscopical and microscopical features may be related to fibrosis of the submucosal layer, because cancer cells neither made a mass in the submucosal layer nor discharged mucin into the lumen because of the fibrosis.

　(5) There were some difficulties in making a diagnosis of early colon cancer occurring in IBD.