Mucosal biopsy of vascular ectasia (angiodysplasia) of the large bowel detected during routine colonoscopic examination.

Between 1975 and 1983, 9434 colonoscopic examinations were performed at the University Hospital of Zürich. Localized vascular ectasia was detected in 84 patients and there were 48 mucosal biopsies from 46 patients. From the total of 48 biopsies only 24 (50%) showed vascular anomalies. The most frequent lesion encountered was groups of thin-walled dilated vessels in the lamina propria seen in 21 biopsies from 20 patients. These dilated vessels are not specific but in respect of age (median 69 years), location (predominantly in the caecum and the ascending colon) and frequent multiplicity, they are suggestive of angiodysplasia. Five of the 20 patients suffered from chronic anaemia due to haemorrhages. The three other positive biopsies (from two patients) revealed a tiny haemangioma in the sigmoid colon of a 28-year-old woman and a few large, thick-walled probably malformed vessels in the mucosa of the caecum of a 17-year-old boy. Twenty-four biopsies did not show any histologically significant vascular anomaly. Mucosal biopsy of vascular lesions detected during routine colonoscopic examination will, if positive, most frequently simply confirm the endoscopically diagnosed vascular ectasia and may in rare cases show or alert suspicion to vascular lesions other than angiodysplasia. Definitive morphological diagnosis will however only rarely be achieved by this method of investigation.