PAEA Surgery End Of Rotation (EOR) Practice Exam

Which type of epithelial benign lesion is most likely to become malignant?

1. Brunner's gland adenoma

2. Tubular adenomas

3. Villous adenomas

4. GISTs

The correct answer is: Villous adenomas

Villous adenomas are considered the type of epithelial benign lesions most likely to progress to malignancy. These lesions are characterized by a frond-like or finger-like projection, and they typically arise in the colon. The risk of progression to colorectal cancer is notably high, particularly with larger villous adenomas. The size of these lesions is a significant factor; those larger than 2 cm have a much higher likelihood of harboring carcinoma or eventually leading to invasive cancer. The histological traits of villous adenomas also contribute to their malignant potential, as they can exhibit dysplastic changes. Understanding the context of other types of adenomas enhances the significance of this option. For example, while tubular adenomas may also have the potential for malignant transformation, their risk is generally lower compared to that associated with villous adenomas. Similarly, Brunner's gland adenomas and gastrointestinal stromal tumors (GISTs) carry different oncogenic risks and are not primarily associated with the same level of progression to malignancy as seen in villous adenomas. In summary, the distinctive morphology and associated risks of malignancy position villous adenomas as the epithelial benign lesions most likely to become malignant.