Abstract
We report a case of arteriovenous malformation of the lower rectum which is very rare in location and in age. A 13-year-old girl who had no genetic abnormality, was admitted to the First Department of Surgery of Yamanashi Medical University with the chief complaint of massive rectal bleeding. Colonoscopy was performed two days after admission, demon-strating a reddish elevated lesion with blood clot in the lower rectum. On 9 days after admission, colonoscopy showed that the elevated lesion was enlarged and entirely reddish. Endoscopic ultrasonography revealed a hypoechoic lesion which was 5mm in size in the mucosal to submucosal layer. It was diagnosed as arteriovenous malformation of the rectum, and endoscopic resection was performed. Histological examination of the resected specimen confirmed the collection of thick-walled, slightly ectatic veins in the mucosal and submucosal layer. Some arteries were shown to coexist. At the surface of the mucosal layer, the artery was ruptured with thrombosis. After endoscopic resection, she had an uneventful course, passing no more blood per rectum during the subsequent 3-year period.
