Though often benign, villous adenomas can become cancerous, and removing them can alleviate this risk, according to the Association of Directors of Anatomic and Surgical Pathology. Surgery removes larger adenomas that gastroenterologists are unable to remove using an endoscope, a specialized tube that doctors insert in the anus.
Villous adenomas are rare, representing approximately 5 percent of adenomas, but 40 percent of villous adenomas lead to cancer, according to the National Center for Biotechnology Information. One study shows that transanal excision, a type of surgery which preserves the sphincter muscle, can effectively remove villous adenomas, though 31 percent of patients had to receive additional treatment for recurring growth. Minor complications from surgery included urine retention, and major complications included a perforated sphincter and postoperative hemorrhaging.
A villous adenoma is a polyp, or tissue growth, on the inner lining of the large or small intestine, explains the Association of Directors of Anatomic and Surgical Pathology. Adenomas with the villous growth pattern can be larger than typical adenomas, which are less than a half inch, and larger growths are more likely to be precancerous. Patients who have previously had any adenomas should have regular colonoscopies to test for new growths, and gastroenterologists may prescribe more frequent colonoscopies for patients with villous adenomas.