直腸に縦走びらんの多発を認めた虚血性大腸炎の1例―縦走びらん多発の意義について

A Case of Ischemic Colitis with Multiple Longitudinal Erosions in the Rectum: A Novel Indicator Suggesting Colorectal Ischemia

要旨　患者は44歳，女性．1日6行の粘血性の下痢，左下腹部痛を主訴に当科を受診．大腸内視鏡検査で横行結腸に線状潰瘍瘢痕と，下行結腸に縦走潰瘍を認め，虚血性大腸炎と診断した．同時に，直腸には，多発する線状の縦走びらんを認めた．更に同様の線状の縦走びらんを認めた8例も合わせて検討すると，この直腸からS状結腸に多発する線状の縦走びらんは虚血性大腸炎の軽微な像と思われた．この所見は若年者にも認められ，2週間から4週間の保存的治療により消失し，また再発例も認めた．直腸からS状結腸に多発する線状の縦走びらんは下血の鑑別診断上念頭に置く必要があると思われた．

　A 44-year-old woman was admitted to our hospital because of lower abdominal pain, muco-bloody stool and low-grade fever. Colonoscopic examination showed three longitudinal ulcers being parallel with the taenia coli in the descending colon. She was diagnosed with typical ischemic colitis, transient type, which was confirmed by the pathological examination of the biopsy specimen. In addition to these lesions, shallow, stringlike, i.e. scratch injury-like erosions aligned in a longitudinal direction were found in the rectum. The biopsy specimen disclosed shedding of superficial epithelia, degenerative atrophy or complete loss of the intestinal glands detaching from the basement membranes (subtle ghost-like appearance), and edema with moderate inflammatory cell infiltration of the lamina propria, suggesting ischemic changes of the rectum.

　We have experienced 9 patients of scratching injury-like erosions of the rectum in the last 2 years and 4 months (Table 1). Case 1 (this case) was associated with typical ischemic colitis. In case 2, the lesions were located in the oral side of the rectal cancer and consistent with obstructive colitis. The scratching injury-like erosions of the rectum in these 2 patients were clearly related to colonic ischemia. Although the other 7 patients did not have any underlying diseases, colonoscopic or barium enema findings were the same as those of case 1 and 2, and the biopsy specimen disclosed ischemic changes. These cases were fairly young (the average age was 29.6). Six out of 7 patients experienced melena. These lesions were spontaneously cured within 2 to 4 weeks.

　We propose that scratching injury-like erosions or multiple longitudinal erosions of the rectum may be a novel indicator of colorectal ischemia.