Hearing that "we found a polyp" during a colonoscopy often causes worry. In reality, it is one of the most reassuring moments in preventive medicine: it means a lesion was spotted — and usually removed — before it had the chance to become anything more serious. This article explains what a polyp is, what the pathology report means and, above all, when endoscopic removal is enough and when surgery is discussed — the question that concerns patients most.
What a colon polyp is
A polyp is a growth of the lining that projects into the bowel. Most are benign, but certain types — mainly adenomas — are considered pre-cancerous: over several years they can progress to cancer. That is precisely why removing them matters — it interrupts that pathway before it begins.
Not all polyps are the same. Hyperplastic polyps are almost always harmless. Adenomas (tubular, villous or mixed) and serrated polyps have the potential to progress and require removal and follow-up. The type is determined only by microscopic (histological) examination.
Removal: polypectomy during colonoscopy
The vast majority of polyps are removed at the same time they are found, during the colonoscopy, in a procedure called polypectomy. It is painless, usually requires no hospital stay, and you return to your activities almost immediately.
For larger or flat polyps there are advanced endoscopic techniques, such as endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD), which allow even extensive lesions to be removed without surgery. Every polyp that is removed is always sent for histological examination.
In the vast majority of cases, colonoscopy does three things at once: it finds the polyp, removes it and sends it for examination — all in a single session.
The pathology report: what the results mean
A few days after removal, the pathology report describes the polyp type and the degree of cellular change (dysplasia). In the vast majority of cases the report is reassuring: a benign polyp that was completely removed. Then nothing more is needed beyond scheduling the next surveillance colonoscopy.
In a small proportion, the report shows that the polyp already contained cancer cells — this is called a "malignant polyp" or early-stage pT1 cancer (invasion limited to the submucosal layer). This raises the crucial question: is the removal already performed enough, or is surgery also needed?
When removal is enough and when surgery is needed
When a polyp turns out to be malignant, the decision is not based on anxiety but on specific histological risk features that estimate the likelihood that cancer cells may have spread to nearby lymph nodes. The pathologist reports, among others:
- Resection margins: whether the polyp was completely removed with clear margins (no cancer cells at the edge).
- Depth of invasion into the submucosa (the Haggitt classification for stalked polyps and Kikuchi/Sm for flat ones).
- Degree of differentiation of the cells (how 'aggressive' the lesion appears).
- Lymphovascular invasion — whether cancer cells are present within small vessels.
- Tumour budding — small clusters of cells at the invasive front.
When there are no high-risk features and removal was complete, the risk of lymph-node spread is very low (in the order of 1–3%). In these cases, the endoscopic removal already performed is often sufficient, followed by close surveillance, with no need for surgery.
When high-risk features are present, however — deep invasion, positive or uncertain margins, lymphovascular invasion, poor differentiation — the risk that cancer cells are in the lymph nodes rises significantly (it can reach 8–23%). Then surgical resection of the bowel segment together with its lymph nodes is discussed, so that any possible focus is removed and accurate staging is achieved.
Not every malignant polyp is operated on — nor should every case simply be watched. The balance between the risk of residual disease and the risk of an unnecessary operation is exactly where individualised surgical judgement makes the difference.
The role of the tumour board
In modern, well-organised settings, the decision about a malignant polyp is not made in isolation. The case is discussed at a multidisciplinary tumour board (MDT) — surgeon, gastroenterologist, pathologist, oncologist — so that the strategy is individualised and evidence-based. The aim is twofold: to leave no residual disease behind, but also to avoid unnecessary operations and their associated morbidity.
If surgery is ultimately indicated, modern laparoscopic and robotic techniques allow an oncologically safe resection through small incisions, with faster recovery and fewer complications. Read more on the pages for colon cancer and rectal cancer.
Follow-up after removal
Even after complete removal of a benign polyp, a repeat colonoscopy is necessary, because anyone who has had one polyp is more likely to develop others in the future. The interval (for example at 3, 5 or 7 years) is individualised according to the number, size and type of polyps. Adhering to this schedule is one of the most effective bowel-cancer prevention measures we have — see also the guide to preventive screening by age.
Does a polyp mean I have cancer?
No. Most polyps are benign. Some types are pre-cancerous, meaning they could progress over time — which is why they are removed. Whether cancer cells are present is shown only by histology, and even then it is usually a very early finding.
Now that the polyp has been removed, do I need another operation?
In the vast majority of cases, no — endoscopic removal is enough. Surgery is discussed only when histology shows cancer cells with high-risk features (deep invasion, positive margins, lymphovascular invasion), where there is a possibility of spread to the lymph nodes.
Is polyp removal painful?
No. Polypectomy is performed during the colonoscopy, under sedation, and is painless. It usually requires no hospital stay and you return to your activities very quickly, with a light diet for the first 24 hours.
Will I develop polyps again?
It is possible. Anyone who has had a polyp has an increased tendency to develop others. That is why repeat colonoscopy at the interval your doctor specifies is crucial, so that any new polyps are removed in good time.
How soon should the next step be decided?
Early cancer within a polyp is not an emergency, but it should not be postponed either. Ideally, the report is assessed and the next step decided within a few weeks, preferably after discussion at a tumour board.