Invasive CA in a Polyp

Comments:
The tumor is considered invasive when it has breached muscularis mucosae to involve submucosa. Adenoma with a focus of invasive adenocarcinoma is referred to as a malignant polyp. They account for 5% of all adenomas.

This whole slide scan of a large polyp shows invasive component clearly invading into the muscularis propria near the center.