RADIOLOGY: GASTROINTESTINAL: GI: Case# 57: MULTIPLE COLONIC/ RECTAL MASSES. Lower abdominal pain and anemia for investigation. There is a 6 x 5 cm soft tissue mass within the rectum. A central high density stalk is seen. The mass has a lobular contour. A second filling defect is seen in the sigmoid colon (2.3 x 1.8 cm) and a third filling defect (1.6 cm) is seen at the junction of the descending colon. Adenomatous polyps appear as soft tissue masses that protrude into the lumen of the bowel. They are usually only detected if they are large or if the colon has been completely evacuated. The CT features of villous adenomas include homogeneous water density (<10 HU) occupying more than half of the lesion and eccentric location on one side of the bowel wall. Dense oral/rectal contrast may obscure some lesions. Air insufflation after colonic cleansing will show the lesions best. Large villous adenomas should be staged by CT because of their malignant potential.