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Image Description

Natural History of Untreated Polyps: Colon polyps are slow-growing tumors. The progression along adenoma-carcinoma sequence is gradual. It takes 5 to 10 years for adenoma to progress to carcinoma. The interval to carcinoma depends upon the polyp size. Smaller polyps are less likely to progress and when they do progress, they require even longer periods to develop cancer.

Serial barium enema studies and rigid sigmoidoscopy studies in the past as well as more recent CT colonography (virtual colonoscopy) have shown that many small polyps can regress and completely disappear. Despite their slow growth rates and evidence of regression, from a clinical standpoint any polyp detected during screening colonoscopy should be removed.

The image shows invasive adenocarcinoma arising in a tubular adenoma. The tumor can be seen invading the muscularis propria.

Image 57 of 113