Colon polyp morphology on double-contrast barium enema: its pathologic predictive value.

The morphologic appearance of 96 polyps seen on double-contrast barium enema was reviewed to assess the predictive value of various signs described to diagnose malignancy. Size, surface contour, basal indentation, and pedunculation were studied. Sessile polyps had an appreciable incidence of malignancy, with size being the best indicator of that risk. Pedunculation was found to be a reliable sign of benignity in predicting the absence of malignant invasion into the adjacent colonic wall. Polyps under 1 cm and having a smooth contour were invariably benign. Conversely, polyps larger than 1 cm with a lobulated contour and basal indentation had a significant incidence of malignancy.