S状結腸に単発した巨大潰瘍の1例

Giant Solitary Ulcer in the Sigmoid Colon, Report of a Case

要旨　患者は80歳，女性．下血にて来院．X線，内視鏡でS状結腸に単発した類円形の深い潰瘍を認めた．潰瘍は腸間膜付着側で，大きさは腸管の1/4周，境界は明瞭，周辺粘膜は異常なかった．その後，約6か月で治癒し，再発はなく，新たに他の部位に病変を生じることもなかった．発症が突然である以外，臨床像に特徴はなく，病理組織像にも特異的所見がないため，鑑別診断は困難であった．画像診断を，白壁の言う点・線・面だけでなく，腸管壁各層の深さをも入れた三次元的，更に時間（経過）因子を入れて四次元的に行い，本症例の診断は，辺縁動脈から分枝した直動脈の障害による極めて限局性の壊死穿孔型の虚血性腸炎の可能性が高いと推察した．

　An 80-year-old woman came to our hospital because of hematochezia. Radiographic and endoscopic examinations revealed a solitary ovoid deep ulcer in the sigmoid colon. The ulcer was located on the mesenteric side and was a quarter of the circumference in size. It was surrounded by normal mucosa and resolved in 6 months. No other lesions was found and no recurrence was noted. Clinical course was not remarkable other than the abrupt onset of symptoms; histopathological examination revealed no specific findings. To make a pictorial diagnosis, as opposed to the two dimensional analysis proposed by Dr. Shirakabe, we made a three dimensional analysis including the depth of the lesion in the colon and even a four dimensional analysis considering the time course of the lesion. We concluded that a disturbance in blood supply in the distribution of the inferior mesenteric artery might have caused necrosis and ulceration, and that this may represent a limited form of ischemic colitis in the sigmoid colon.