亜輪状潰瘍を示した虚血性大腸炎の1例

Ischemic Colitis, Report of a Case

要旨　61歳，女性の亜輪状潰瘍を示した虚血性大腸炎を報告した．患者は突然の下腹部灼熱感と下血を訴えて来院し，X線検査でS状結腸に，中心に浅い不整なバリウム斑とこれを取り巻く周囲に輪状の隆起を思わせる透亮像を伴う潰瘍像がみられたが，栂指圧痕像や縦走潰瘍はみられなかった．内視鏡検査でS状結腸に辺縁平滑な浅い亜輪状の潰瘍がみられ，潰瘍底は小結節状の隆起と出血を伴っていた．生検の組織診では悪性の所見はみられなかったが，潰瘍修復の遅延を認めたので悪性も否定できず発症より45日目にS状結腸切除術が施行された．切除標本では粘膜集中像を伴う大きさ2.7×1.3cmの亜輪状潰瘍がみられた．H・E染色標本の病理組織診で病巣はUl-Ⅰを呈した非特異性潰瘍と診断されたが，鉄染色で潰瘍底に担鉄細胞が証明され虚血性大腸炎と診断された．

　A 61 year-old woman visited Funada Hospital complaining of sudden onset of burning sensation in the lower abdomen and melena. Barium enema study performed next day showed irregular barium flecks and rigidity of the sigmoid colon. Thumb-printing, sacculation and tubular narrowing, however, were not found. Endoscopic examination on the 7 th day after the onset showed edematous mucosa surrounding the shallow ulceration of sub-circular form with bleeding areas and notches in the base.

　She was admitted to Sendai City Medical Center Hospital on the 16 th day after the onset in order to have further examinations. The second endoscopic examination at about four weeks after the onset showed predominantly edematous mucosa (like tumor change) surrounding the shallow ulceration with irregular white coating and red patches, and the third at about six weeks after the onset showed non-swollen converging folds around the shallow ulceration with monotonous white coating.

　Histological study of the biopsy specimen showed decreasing of goblet cells, hemorrhage, congestion and invasion of eosinophilic substance in mucosal layer. Since the possibility of malignancy was not completely ruled out, she underwent an operation on the 45 th day after the onset.

　The resected specimen showed a sub-circular ulceration of 2. 4 X 1. 3 cm in size with converging folds in the sigmoid colon. Histological examination revealed Ul-I ulceration and predominantly fibrous and vascular granulation tissues in the ulcer base with partially regenerative epithelium surrounding ulceration. Iron staining was positive in the ulcer base. Based on these histological findings, the patient was finally diagnosed as having had transient ischemic colitis.