From the Guidelines
Yes, sessile polyps can be adenomatous, and their removal is crucial to prevent malignant transformation and reduce cancer risk. Sessile polyps are growths that are flat or slightly raised on the surface of the colon or rectum, lacking a stalk. Adenomatous polyps are a specific histological type characterized by abnormal glandular tissue that has the potential to develop into colorectal cancer. In fact, many adenomatous polyps are sessile in their morphology, and according to the most recent guidelines, sessile serrated adenomas/polyps are considered precancerous lesions 1.
The risk of malignant transformation depends on several factors, including the size of the polyp (larger than 1 cm carries higher risk), the degree of dysplasia, and specific histological features. Sessile adenomatous polyps can sometimes be more challenging to remove completely compared to pedunculated polyps (those with stalks), often requiring techniques such as endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) 1.
Some key points to consider:
- Sessile serrated lesions (SSLs) that appear associated with a higher risk of future neoplasia or colorectal cancer (SSLs ≥10 mm or serrated lesions harbouring dysplasia including traditional serrated adenomas) should be offered a one-off colonoscopic surveillance examination at 3 years 1.
- The detection of sessile serrated polyps (SSPs) is a major deficiency of sigmoidoscopy and CT colonography because SSPs are predominantly in the proximal colon and tend to be flat 1.
- Complete removal of sessile adenomatous polyps is essential to prevent recurrence and reduce cancer risk, and follow-up surveillance colonoscopies are typically recommended based on the number, size, and histology of the polyps found 1.
In terms of management, the Chinese Society of Clinical Oncology (CSCO) recommends that for sessile lesions of >10 mm suspected to be villous adenomas or sessile serrated adenomas/polyps, endoscopic treatment such as EMR or ESD should be considered 1. Overall, the management of sessile adenomatous polyps requires a comprehensive approach, including accurate diagnosis, complete removal, and appropriate follow-up surveillance to reduce the risk of colorectal cancer.
From the Research
Sessile Polyps Classification
- Sessile polyps can be classified as neoplastic or non-neoplastic, with neoplastic polyps having the potential to harbor malignancy 2
- Neoplastic polyps are primarily important because they have a malignant potential, representing a stage in the development of colorectal cancer 2
Adenomatous Polyps
- Most neoplastic polyps do not evolve into cancer, but it is well accepted that the majority of colorectal carcinomas evolve from adenomatous polyps 2
- The sequence of events leading to this transformation is referred to as the adenoma-to-carcinoma sequence 2
Sessile Serrated Polyps
- Sessile serrated polyps (SSPs) are a type of neoplastic polyp that can be difficult to detect and remove 3, 4
- SSPs have been implicated in the development of interval cancers and can progress rapidly to colorectal cancer 3, 4
- Endoscopic mucosal resection (EMR) is a safe and effective technique for the resection of SSPs, with a low local recurrence rate 3
Management of Sessile Polyps
- The management of sessile polyps depends on their size, shape, and location, as well as the presence of dysplasia or malignancy 5, 6
- Large sessile polyps can be removed using EMR or endoscopic submucosal dissection (ESD), while smaller polyps can be removed using hot snare or cold snare 5, 6
- Surveillance colonoscopies are important for detecting local recurrences and preventing the development of colorectal cancer 3