Treatment Options for Rectal Villous Adenomas

According to the World Health Organization (WHO), rectal villous adenomas are classified into three types based on histological structure: tubular, tubulovillous, and villous. These classifications depend on the percentage of villous component present in the tumor. Specifically, tubular adenomas contain less than 25% villous tissue, tubulovillous adenomas range between 25% and 75%, and villous adenomas consist of more than 75% villous elements.

Understanding the Risk of Malignant Transformation

The likelihood of a villous adenoma becoming cancerous is closely linked to the presence of dysplasia, particularly high-grade or severe atypical hyperplasia. In fact, severe dysplasia is now considered a critical transitional stage between benign adenomas and invasive cancer. Other factors that influence the risk of malignancy include the size of the lesion, its anatomical location, whether it is pedunculated or sessile, surface characteristics, and the patient's age.

Why Early Intervention is Crucial

Pure villous adenomas carry a significant risk of malignancy, with reported cancer transformation rates reaching up to 32%. Due to this high risk, most medical experts agree that tubulovillous and villous adenomas should be regarded as premalignant lesions. As such, early surgical removal is strongly recommended to prevent progression to cancer and ensure better long-term outcomes for patients.

Recommended Treatment Approaches

Management typically involves complete excision of the lesion, either through endoscopic techniques or open surgery, depending on the size, location, and depth of invasion. Regular follow-up with colonoscopies is also essential to monitor for recurrence or the development of new lesions. In cases where high-grade dysplasia or early cancer is detected, more aggressive treatment may be warranted.