Sessile Serrated Polyp: What It Is and What Comes Next
A sessile serrated polyp (SSP) is a flat, pale growth in the lining of the colon. It is a true precursor to colorectal cancer, and it is easy to miss. The good news is that it can be removed during a colonoscopy, and the way it is removed and followed up has a large effect on whether it comes back. If your report says “sessile serrated polyp,” “sessile serrated lesion” or “sessile serrated adenoma,” the sections below explain what that means for you. Our team at Precision Digestive Health in South Plainfield, NJ performs colonoscopy and colon cancer screening, so we write this the way we would explain it across the exam table.
Precision Digestive HealthUnderstand Your Colonoscopy FindingsDr. Meet Parikh provides colonoscopy and colon cancer screening in South Plainfield, with care for digestive health concerns.Visit
TL;DR
- Sessile serrated polyp, sessile serrated lesion (SSL) and sessile serrated adenoma describe the same type of flat colon polyp. SSL is the newer preferred term.
- These polyps are precursors of an estimated 20% to 30% of colorectal cancers and sit mostly in the right (proximal) side of the colon.
- Complete removal matters most. Small ones are usually taken with a cold snare, and larger ones with endoscopic mucosal resection (EMR).
- Most guidelines call for a repeat colonoscopy in 3 years after a large or dysplastic SSL, and the exact interval depends on size, number and pathology.
- Having one SSP is different from serrated polyposis syndrome, which requires a high polyp burden.
Table of Contents
- One polyp, three names
- Why a flat polyp deserves attention
- What a sessile serrated polyp looks like
- How a sessile serrated polyp is removed
- When to repeat your colonoscopy
- Is one polyp the same as serrated polyposis syndrome?
- Can diet or lifestyle shrink or prevent them?
- Who should be screened, and when
- Colonoscopy with Dr. Parikh in South Plainfield
- Our perspective on serrated polyps
- FAQ
- Sources
One polyp, three names
The vocabulary confuses almost everyone. Pathologists have used “sessile serrated adenoma,” “sessile serrated polyp” and “sessile serrated lesion” for the same finding. A 2020 pathology review describes “sessile serrated lesion” as the term that has replaced the older two, partly because many of these lesions do not show dysplasia (abnormal cell growth) under the microscope, so “adenoma” was misleading.
The NCI dictionary lists three types of serrated polyps: hyperplastic polyps, sessile serrated polyps (also called sessile serrated adenomas) and traditional serrated adenomas. The name “serrated” refers to the saw-tooth pattern the glands make when a pathologist examines the tissue. “Sessile” means the polyp sits flat against the wall rather than hanging from a stalk.
If you saw “serrated adenoma” on a report, it is the same family of findings, and your gastroenterologist can tell you which exact type was found and whether dysplasia was present. That detail drives your follow-up.
Why a flat polyp deserves attention
Not all polyps carry the same risk. Many people think of the classic mushroom-shaped adenoma as the cancer-causing polyp. Serrated polyps follow a different route. Research reviews describe SSPs as precursor lesions of 20% to 30% of colorectal cancers, with the serrated polyp-to-cancer sequence occurring mainly in the proximal colon.
Three features make them a special concern:
- They are flat. A flat, pale lesion blends into the surrounding lining.
- They favor the right colon. One study summarized in a systematic review of endoscopic diagnosis found SSPs in the proximal colon 81.8% of the time, versus 44.4% for hyperplastic polyps.
- They tend to be larger. The same review cites an average SSP size of 14.2 mm against 6.2 mm for hyperplastic polyps in one study.
The proximal colon is also the area where bowel prep is most likely to leave residue. That is why a thorough prep and an unhurried exam are not formalities. A flat polyp under a film of stool can be overlooked.
What a sessile serrated polyp looks like
You cannot see one at home and no symptom reliably signals one. Most people with SSPs feel nothing. During colonoscopy, the physician looks for a set of visual clues.
According to Parsa and Rex, common features include:
- A pale color, close to the surrounding lining
- Indistinct, hard-to-trace edges
- A flat or slightly raised shape
- An adherent cap of mucus on the surface
The systematic review of endoscopic diagnosis lists further candidate clues: location in the proximal colon, size over 10 mm, irregular shape, a cloudlike surface, a rim of debris, dilated vessels and dilated crypts. Its authors note that more prospective studies are needed to validate these features, which is one reason that the final answer always comes from the pathologist, not from the camera.
There is also a technical wrinkle. The same Parsa and Rex review notes that the NICE type 1 pattern does not separate hyperplastic polyps from SSPs, while the WASP classification points to irregular surfaces, indistinct edges, a cloudlike appearance and large open pits. In plain terms, a skilled endoscopist uses several clues together, with good lighting and a clean colon.
How a sessile serrated polyp is removed
The goal is complete removal, in one session whenever possible. Recurrence depends heavily on complete resection, and incomplete removal of a flat lesion is a known pitfall.
Small polyps: cold snare
For SSPs under 10 mm, a 2019 review of treatment and surveillance names cold snare polypectomy as the preferred method. A thin wire loop captures the polyp and a margin of normal tissue, without electrical current.
Obuch and colleagues recommend that sessile polyps larger than 3 mm be removed with a cold or hot snare rather than biopsy forceps, since forceps can leave part of a flat lesion behind. They add that narrow-band imaging or chromoendoscopy can help the endoscopist see the perimeter and confirm nothing remains.
Larger polyps: EMR
For lesions over 10 mm, the same 2019 review names endoscopic mucosal resection as the preferred technique. In EMR, liquid is injected under the lesion to lift it. Obuch and colleagues note that dye-containing liquid can both elevate the polyp and outline its edges, which helps the endoscopist judge the margins, and that any residual tissue should be removed completely.
What happens afterward
The polyp goes to a pathologist, and results typically arrive within one to two weeks. Our article on polyp removal recovery covers what to expect in the days after the procedure and when to call us.
When to repeat your colonoscopy
There is no single interval for everyone. US guidance has long based serrated-polyp surveillance intervals on size and histology, including whether an SSL has dysplasia.
A 2021 review for surgeon endoscopists states that most current guidelines recommend a 3-year interval for:
| Finding | Typical surveillance interval |
|---|---|
| SSL of 10 mm or larger | 3 years |
| SSL with dysplasia | 3 years |
| Three or more SSLs under 10 mm | 3 years |
| Traditional serrated adenoma, any size | 3 years |
For other findings, such as one or two small SSLs without dysplasia, the interval is set by your gastroenterologist from the full report, your family history and the quality of the prep. Two things can shorten it: a prep that left parts of the colon poorly seen, or a piecemeal resection where complete removal is uncertain.
To see how serrated findings fit into the wider picture, read our guides to adenoma surveillance intervals and colonoscopy frequency. Our overview of colon polyp types that need closer surveillance is useful if your report mentions size or villous features.
Is one polyp the same as serrated polyposis syndrome?
No. A single sessile serrated polyp is a common finding. Serrated polyposis syndrome (SPS) is a clinical diagnosis with a much higher burden. A review of serrated polyps and SPS explains that the WHO criteria are met by any one of these:
- More than 20 serrated polyps distributed throughout the colon
- At least 5 serrated polyps proximal to the sigmoid colon, with 2 or more larger than 10 mm
- Any number of serrated polyps proximal to the sigmoid colon in a person with a first-degree relative who has SPS
People with SPS need specialized, high-quality colonoscopy and a closer surveillance plan. If you have many serrated polyps, or a parent, sibling or child with SPS, tell us so we can review your history and plan accordingly.
Can diet or lifestyle shrink or prevent them?
No food has been shown to shrink an existing sessile serrated polyp, and removal is the way to deal with one. Lifestyle does still matter for the polyps you may develop later. A 2023 study in the Journal of Gastroenterology found that smoking was associated with an increased risk of serrated polyps, and other lifestyle factors showed effects that differed by polyp pathway. Not smoking is the clearest step supported by that research.
Our practice also offers nutrition counseling, which can help you build eating habits around your overall digestive health after a procedure.
Who should be screened, and when
Because SSPs rarely cause symptoms, screening colonoscopy is how most are found and removed. Our guide to colonoscopy at age 45 explains when to start and what to expect, and why colonoscopies matter for long-term health explains the reasoning behind early detection. If you have a family history of colorectal cancer or polyps, bleeding, a change in bowel habits or unexplained anemia, see a gastroenterologist rather than waiting for a screening date.
Colonoscopy with Dr. Parikh in South Plainfield
If you have a polyp report to review, are due for a repeat exam or have never been screened, Dr. Meet Parikh is a board-certified, fellowship-trained gastroenterologist who performs colonoscopy and colon cancer screening in South Plainfield, NJ. Visits can be held in English, Gujarati, Hindi or Spanish. We follow patients after the procedure with treatment planning and ongoing care.
You can read about our colonoscopy service or colon cancer screening, then book an appointment through our website.
Our perspective on serrated polyps
Patients are often told they had a “precancerous polyp” and are left wondering whether it was serious. With a sessile serrated polyp, the honest answer is that it matters, and that the colonoscopy did its job by finding it. We think the most useful conversation after a polyp finding has three parts: what type it was, whether it was removed completely, and when the next exam is due. Those three answers turn a worrying word into a plan. Our approach is patient-centered. We take time to explain the pathology report in plain language, in English, Gujarati, Hindi or Spanish, and we set the follow-up schedule around your findings and history rather than a one-size-fits-all number. Precision Digestive Health
FAQ
Is a sessile serrated polyp cancer?
No, it is not cancer when found and removed. It is a precancerous lesion, and SSPs are precursors of 20% to 30% of colorectal cancers. Removal during colonoscopy is how the risk is addressed.
Is a sessile serrated lesion the same as a sessile serrated adenoma?
Yes, in practice. A pathology review describes sessile serrated lesion as the term that replaced sessile serrated adenoma and sessile serrated polyp. Your report may use any of the three, and all describe the same kind of flat serrated polyp.
What does a sessile serrated polyp look like?
It is typically pale, flat, with indistinct edges and often a cap of mucus on top. Endoscopists use these features together, and the pathologist confirms the diagnosis after removal.
How soon do I need another colonoscopy after one is removed?
It depends on size, number and whether dysplasia was found. Most guidelines suggest 3 years for an SSL of 10 mm or more, one with dysplasia, three or more small ones, or a traditional serrated adenoma. Your gastroenterologist sets your exact date.
Sources
- Evolving pathologic concepts of serrated lesions of the colorectum
- Endoscopic recognition of the sessile serrated polyp to cancer sequence
- Endoscopic diagnosis of sessile serrated polyp: a systematic review
- Optimal endoscopic treatment and surveillance of serrated polyps
- Sessile serrated polyps: detection, eradication, and prevention
- Serrated polyps and polyposis of the colon: a brief review
- Guidelines for colonoscopy surveillance after screening and polypectomy
- Serrated polyps and serrated polyposis syndrome
- Hierarchical contribution of individual lifestyle factors to colorectal polyp pathways
