Large sessile adenomas are associated with a high prevalence of synchronous advanced adenomas

The prevalence of synchronous neoplasia in patients with large sessile colorectal adenomas is uncertain.

We conducted a retrospective single-center review of synchronous neoplastic findings in 190 consecutive patients with intact colons and single large sessile adenomas resected endoscopically. Synchronous polyps were those removed at the colonoscopy that discovered the large sessile adenoma or at any follow-up endoscopic examination within 12 months of discovery of the large sessile adenoma.

Seventy-five percent of patients had at least 1 synchronous adenoma, and the 190 patients had a mean of 4 synchronous adenomas. Thirty percent of patients had > or =1 synchronous advanced adenoma (adenoma > or =1 cm in size or with high-grade dysplasia or villous elements). There were a total of 116 synchronous advanced adenomas, including 89 adenomas 10-19 mm in size and 8 that were > or =20 mm in size.

Colonoscopists should be aware that patients with large sessile adenomas have a high prevalence of synchronous advanced neoplasia. Prospective study of this issue is warranted.