The short answer
A polyp is a growth that sticks out from a body lining, like the inside of the colon. A tumor is any abnormal mass of tissue, which can be benign or cancerous. The words overlap: some polyps are tumors, and certain polyps can turn into cancer over time, which is why they are often removed.
A polyp is a growth that projects from a lining, such as the inside of the colon.
A tumor is any abnormal mass of tissue and can be benign (not cancer) or malignant (cancer).
The terms overlap: some polyps are a type of tumor, and some can become cancer over time.
Because certain polyps carry a risk of turning into cancer, doctors often remove them during procedures like colonoscopy.
On this page
Choose how you want to read this
The whole article, with every detail and caution.
This page is for anyone who has been told they have a polyp or a tumor. It explains what each word means, where they overlap, and why doctors often remove polyps.
The short version
A polyp is a growth that sticks out from a body lining — like the inside of the colon. Some can become cancer. A tumor is any abnormal mass of tissue, which can be benign (not cancer) or malignant (cancer). The words overlap: some polyps are a type of tumor, and certain polyps can slowly turn into cancer, which is why doctors often remove them. Finding either does not mean you have cancer.
What a polyp is
A polyp is a piece of tissue that grows out from a lining, often on a little stalk or as a raised bump. Colonic polyps grow in the colon, and doctors find and remove them during colonoscopy. MedlinePlus says most colon polyps do not cause noticeable signs.
What a tumor is
"Tumor" is a broader word. It simply means an abnormal lump of tissue that forms when cells grow more than they should. A tumor can be benign, meaning it stays put and is not cancer, or malignant, meaning it is cancer and can spread. So a tumor is not automatically cancer.
Where the words overlap
Here is the part that confuses many people: a polyp can be a tumor, since a polyp is a kind of growth. The important question is not "polyp or tumor?" but "is it benign, or has it started to become cancer?" That is why tissue is examined rather than judged by shape alone.
Why doctors remove polyps
Some polyps may develop into cancer or already be cancer. For that reason, doctors remove them during colonoscopy and have them tested by a pathologist, a doctor who examines tissue under a microscope. Finding and removing polyps is a main reason colon screening matters.
What to ask your team
If a polyp or tumor was found, helpful questions include:
- Was it removed and tested?
- Is it a type that can become cancer?
- Do I need follow-up or repeat screening, and when?
The pathology report on the tissue is what turns uncertainty into a clear answer, so ask what it showed.
When to get help sooner
Most colon polyps cause no symptoms at all. Still, some changes are worth reporting rather than watching.
- Call 911 or go to an emergency department if bleeding from the bottom is heavy or will not stop, or if any bleeding comes with feeling faint, a racing heart, or severe belly pain. Do not drive yourself.
- Call your care team the same day if you see blood in your stool, or blood on the toilet paper or your underwear after a bowel movement.
- Call your care team within a day or two if constipation or diarrhea lasts more than a week.
These signs do not mean you have cancer. They mean the cause should be checked.
Sources
Common questions
What is the difference between a polyp and a tumor?
A polyp is a growth that sticks out from a body lining, and some can become cancer. A tumor is any abnormal mass of tissue, which may be benign or cancerous. The terms overlap, because some polyps are a type of tumor and some can become cancer over time.
Does finding a polyp mean I have cancer?
Not necessarily. MedlinePlus says some polyps may develop into cancer or already be cancer, which is why doctors remove and test them. The test result tells you which it is.
Why are polyps removed if they are usually harmless?
Some polyps may develop into cancer or already be cancer. Removing one during a procedure like colonoscopy lets a pathologist examine it.
Is a tumor always cancer?
No. A tumor is simply an abnormal lump, and many tumors are benign, meaning they are not cancer. A biopsy or removal, followed by examination under a microscope, is how doctors tell benign from cancerous.
Questions to ask your doctor
Being prepared helps you get the most out of your appointments. Save or print these questions.
Tap a question to save it to your list (kept on this device).
More words from this kind of report
Other guides in biopsy & pathology reports.
Your next step
Plain-language definitions for both sides of the comparison.
Talk with a trained specialist or navigator
Cancer Explained provides educational guidance, but does not replace trained specialists, social workers, or your medical team.
Talk to a trained cancer information specialist
Free, confidential assistance from NCI Cancer Information Service via phone, chat, or email.
Contact your oncology team
Locate after-hours contact numbers, portal messages, or urgent triage phone lines.
Find a patient navigator
Get one-on-one help with appointments, logistics, translation, and care coordination.
Find a genetic counselor
Discuss inherited mutation risk, family history, and genetic testing options.
Find an oncology social worker
Access emotional counseling, family support groups, and mental health resources.
Find a financial navigator
Locate copay assistance foundations, grant programs, and lodging/travel support.
Find a clinical-trial specialist
Search matching studies and speak with NCI trial information specialists.
Get urgent help
Fever of 100.4°F (38°C) or higher during chemo, severe pain, or trouble breathing: call your cancer care team right away, day or night. Call 911 for an emergency.
Plain-language explanation of the published sources cited on this page. AI-assisted, source-checked, not clinician-reviewed.
Last updated: 2026-10-02Next planned review: 2027-07-14
Review details and limits
Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes, and this is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status — Source checked. This page was written with AI assistance and then compared with the sources listed on it, looking for statements those sources do not back up. That check is not a sentence-by-sentence record and can miss errors. It is not a medical review, and it does not confirm the page is complete or right for your situation.
General education. Low-risk educational or organizational content. Medical facts are cited to authoritative sources.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
Words to know
Tap any term to see what it means.
How this page was created
Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes, and this is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status: Source checked — This page was written with AI assistance and then compared with the sources listed on it, looking for statements those sources do not back up. That check is not a sentence-by-sentence record and can miss errors. It is not a medical review, and it does not confirm the page is complete or right for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
Read more about our editorial process, our use of AI, and our corrections policy.
Spotted a problem? Report an error — a factual mistake, broken or outdated source, confusing wording, or anything that seems unsafe. Please do not include names, medical record numbers, dates of birth, addresses, or other identifying medical information in your report.
After using this page, do you understand what to do next?
Anonymous — we only record the answer, never who gave it.