What is the recommended treatment for a flat polypoidal lesion in the caecum that shows high grade dysplasia?

The recommended treatment for a flat polypoidal lesion in the caecum exhibiting high-grade dysplasia is right hemicolectomy. High-grade dysplasia is considered to be a precursor to cancer, and lesions that demonstrate this level of abnormality are viewed with significant concern for potential malignancy.

Given the risk for progression to colorectal cancer, especially with lesions in the colon, complete excision is often necessary to ensure that all potentially cancerous cells are removed. A right hemicolectomy allows for the resection of the affected segment of the colon, along with a margin of healthy tissue, which helps to minimize the risk of residual disease.

Other treatment options, such as colonoscopy, might be useful for diagnostic purposes or for the removal of smaller polyps, but in cases of high-grade dysplasia, they may not suffice for complete treatment. Additionally, radiotherapy and chemotherapy are generally used for more advanced stages of cancer rather than for lesions primarily diagnosed as high-grade dysplasia without invasive characteristics. Therefore, the surgical approach of right hemicolectomy is the most appropriate and effective treatment strategy in this scenario.