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recurrent colorectal adenoma

Friday 9 March 2012

Recurrent adenomas result from the appearance of new adenomas, continued growth of an incompletely resected adenoma, or detection of a previously undetected but pre-existing adenoma.

The overall recurrence rates for new adenomas are estimated at 20% to 60% with average follow-up times of 3 to10 years after index polypectomy.

Most recurrences occur in the first 2 years following polypectomy.

The estimated time to finding new adenomas is 58 months for patients clear on the first colonoscopy and 16 months for patients who had adenomas on the first examination.

In 18% of patients, the adenomas arise proximal to the splenic flexure.

Villous tumors,particularly broadly sessile ones, usually have a less well-defined border than do tubular adenomas and, therefore, have a greater tendency to recur after localre section than smaller, pedunculated adenomas.

Endoscopic follow-up studies to evaluate new adenomas are hampered by the fact that as many as 25% to 27% of adenomas measuring @<@ 5 mm in diameter and up to 6% ofadenomas measuring 1 cm in diameter are missed during one endoscopic examination.

Right-sided adenomas are missed more often (27%) than left-sided adenomas (21%).

Lesions measuring up to 8 cm in diameter may be missed, and some of these may contain areas of malignancy.