From the Guidelines
Sessile serrated lesions (SSLs) of the colon should be completely removed, typically via endoscopic mucosal resection (EMR) with a submucosal injection technique, to ensure complete excision and prevent progression to colorectal cancer. The diagnosis of SSLs is often challenging due to their flat appearance, pale color, and indistinct borders, making high-quality bowel preparation and careful inspection essential for their identification [ 1 ].
Key Considerations for Removal
- For non-pedunculated lesions (10–19 mm), cold or hot snare polypectomy (with or without submucosal injection) is suggested for removal [ 1 ].
- EMR should be considered for non-polypoid and serrated lesions in the 10- to 19-mm size range, as conventional polypectomy techniques may pose challenges for complete endoscopic removal [ 1 ].
- The use of a microprocessor-controlled diathermy unit, careful use of diathermy, and achieving complete endoscopic resection in the first attempt may help reduce the incidence of complications and recurrence of these lesions [ 1 ].
Surveillance Recommendations
- Following removal, surveillance colonoscopy is recommended at 3 years for SSLs ≥10mm, SSLs with dysplasia, or if multiple SSLs are found [ 1 ].
- For smaller, isolated SSLs without dysplasia, surveillance at 5 years is appropriate [ 1 ].
- Patients with serrated polyposis syndrome (SPS) should be offered one to two yearly colonoscopic surveillance [ 1 ].
Clinical Significance
- SSLs are clinically significant because they can progress to colorectal cancer through the serrated neoplasia pathway, which accounts for approximately 15-30% of colorectal cancers [ 1 ].
- This pathway differs from the traditional adenoma-carcinoma sequence and often involves BRAF mutations and CpG island methylator phenotype [ 1 ].
From the Research
Diagnosis of Sessile Serrated Adenoma (SSA) or Sessile Serrated Lesion (SSL)
- Serrated lesions of the colorectum, including SSA/P, are precursors to perhaps one-third of colorectal cancers (CRCs) 2
- SSA/P should be classified pathologically according to the World Health Organization criteria as hyperplastic polyp, sessile serrated adenoma/polyp (SSA/P) with or without cytological dysplasia, or traditional serrated adenoma (TSA) 2
- Serrated lesions have a distinct endoscopic appearance, and several lines of evidence suggest that on average they are more difficult to detect than conventional adenomatous polyps 2
Treatment of Sessile Serrated Adenoma (SSA) or Sessile Serrated Lesion (SSL)
- Effective colonoscopy requires an endoscopist trained in the endoscopic appearance of serrated lesions 2
- It is recommended that all serrated lesions proximal to the sigmoid colon and all serrated lesions in the rectosigmoid > 5 mm in size, be completely removed 2
- Endoscopic mucosal resection (EMR) is a safe and effective technique for the resection of large sessile serrated polyps (SSPs) 3
- Piecemeal cold snare polypectomy (p-CSP) is technically equally efficacious to EMR but virtually eliminates the risk of delayed bleeding and perforation 4
- Emerging endoscopic techniques such as underwater polypectomy, suction pseudopolyp technique, and piecemeal cold snare polypectomy are helpful tools for the endoscopist's armamentarium for removing SSA/Ps 5
Post-Polypectomy Surveillance
- Recommendations are made for post-polypectomy surveillance of serrated lesions and for surveillance of serrated polyposis patients and their relatives 2
- Patients with confirmed SSA/Ps and proximal HPs should undergo surveillance at intervals similar to what is recommended for patients with conventional adenomas 5
- Recurrence rates following p-CSP were similar to EMR at 4.3% (n=4) versus 4.6% (n=14) and 2.0% (n=1) versus 1.2% (n=3) for surveillance colonoscopy (SC)1 and SC2, respectively 4