Abstract
A 75-year-old man was admitted to our hospital because of prolapse of a tumor from the anus, which had developed over three years. Rectal examination revealed a soft tumor 5-6 cm proximal to the anal verge. Barium enema study showed a tumor, about 7 cm in diameter and having a cauliflower-like appearance, in the lower rectum. Endoscopic study revealed a lobulated tumor with a granular surface, which was coated with copious mucus. CT scan showed a homogeneous tumor whose margin was similar in appearance to brain gyrus. Endoscopic ultrasonography was suggestive of tumor invasion to the muscularis propria. Ulceration and induration of prolapsed tumor were not observed. Pull-through operation was performed. The resected specimen showed a wide-base tumor measuring 8.5×8.0 cm. Histological findings confirmed it to be a villous adenoma with no evidence of malignant change.
