上行結腸に原発したびまん浸潤型大腸癌の1例

Diffusely Infiltrating Carcinoma of the Ascending Colon, Report of a Case

要旨　上行結腸に原発した比較的まれなびまん浸潤型大腸癌の1例を経験したので報告した．患者は28歳，男性．主訴は右下腹部痛．注腸検査で上行結腸に壁不整硬化，cobblestone様所見を認めた．内視鏡所見では同部に易出血性の浅い陥凹性病変が存在し，周囲に浮腫状の粘膜を認めた．炎症性腸疾患が強く疑われたが，3回目の生検で癌細胞が証明され，右半結腸切除術が施行された．病理所見はリンパ管浸潤の強い中分化腺癌であった．術後免疫，化学療法剤の投与を受け，手術後32か月の現在，再発なく健在である．本症の診断に当たり，特に右側発生の場合，炎症性腸疾患との鑑別が問題になると思われた．

　Diffusely infiltrating cancer of the right colon is rare. Only sixteen cases have been reported in the Japanese literature. We report here the 17 th case.

　A 28-year-old male was admitted with the complaint of right lower abdominal pain.

　A localized mass was palpated in that region. Barium enema study revealed an asymmetric narrowing and cobblestone-like appearance of the ascending colon, leading to a diagnosis of Crohn's colitis. The third biopsy, however, was positive for adenocarcinoma.

　X-ray examination of the stomach showed no abnormality. Under the diagnosis of primary cancer of the ascending colon, right hemicolectomy was performed with extensive lymph node dissection. The patient has been asymptomatic for the 32 months since then.

　Some clinical and pathologic characteristics of this condition are discussed, based on literature review. It seems to be important to differentiate this condition from inflammatory bowel disease and metastatic cancer of the colon.