Which of the following factors increases the risk of malignancy in colonic polyps?

Villous histology is a key factor that significantly increases the risk of malignancy in colonic polyps. Polyps with a villous architecture are associated with a higher likelihood of containing carcinoma or being precursors to malignant lesions. Villous adenomas, in particular, have a propensity for malignant transformation; the larger the villous component, the more concerning it becomes. In contrast to tubular adenomas, which typically have a lower risk of cancer, villous adenomas present a greater risk of progressing to colorectal cancer.

The size of polyps, while relevant, does not inherently mean that smaller polyps are more or less likely to be malignant. Non-dysplastic features and low epithelial dysplasia suggest a lower risk for malignancy as these features indicate that the cells have not yet undergone the significant changes associated with cancer development. Therefore, recognizing the histological pattern, particularly the presence of villous histology, is critical for assessing the potential risk of malignancy in polyps.