Desmoid Tumor: Causes, Symptoms, and Treatment
Medically reviewed by Achuta Uppu, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Desmoid Tumor?
A sarcoma specialist, a doctor who treats tumors that grow from connective tissue, usually leads care for a desmoid tumor. A medical oncologist, a cancer doctor, and a surgeon may also help. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is a desmoid tumor?
A desmoid tumor is an abnormal growth that starts in connective tissue, the tissue that gives strength and flexibility to bones, ligaments, and muscles. It is generally noncancerous because it does not spread to other parts of the body. Still, it can invade nearby tissue and can be hard to remove with surgery.
Doctors also call it aggressive fibromatosis or desmoid-type fibromatosis. Because connective tissue is found everywhere in the body, a desmoid tumor can occur anywhere. These tumors are often found in the abdomen, shoulders, upper arms, and thighs. They are rare.
Symptoms
Some people have no symptoms. When symptoms do occur, the most common one is pain. Symptoms can include:
- Pain.
- Swelling in the area of the tumor.
- Sleep loss.
- Trouble moving the affected body part.
A tumor inside the belly can block the bowel, which can cause constipation. A tumor in an arm or leg can limit how well a joint moves. Some tumors are found by chance when a person has an imaging test for another reason.
Causes and who gets it
Most desmoid tumors are not inherited. They are caused by gene changes that happen during a person's lifetime. Changes in a gene called CTNNB1 account for around 90 percent of tumors that are not part of familial adenomatous polyposis (FAP). FAP is an inherited form of colon cancer. Desmoid tumors are found in 10 to 30 percent of people with FAP.
Desmoid tumors are most common in people between the ages of 15 and 60. They are more common in females than in males.
How doctors diagnose it
If you have symptoms, your doctor may use imaging scans such as CT, MRI, or ultrasound to see where the tumor is and how big it is. To check that it is a desmoid tumor, the doctor does a biopsy, which takes a small amount of the tumor out with a needle. A pathologist, a doctor who studies cells, looks at the cells under a microscope. Depending on where the tumor is, a biopsy may be hard to do.
Treatment
Treatment is different for each person, so NCI advises seeing an expert in sarcoma treatment to choose the best approach. Desmoid tumors can be hard to predict. They can shrink and go away on their own, stay the same size, or grow quickly. Options to talk about with your doctor include:
- Watch and wait. If a tumor grows very slowly or shrinks, it may be safest for the doctor to check it regularly without treating it.
- Surgery. It has been a standard treatment in the past, but this may be changing because the tumor often returns to the same place after surgery.
- Radiation therapy. It is an option for some tumors, but it can cause other cancers in the future, so talk about alternatives with your doctor.
- Chemotherapy, which uses drugs to kill fast-growing cells. There is no standard chemotherapy for desmoid tumors, but promising new drugs have been shown to shrink them.
In November 2023, the FDA approved a medicine called nirogacestat (Ogsiveo) for adults whose desmoid tumors are growing and who need treatment that works throughout the body. It was the first approved treatment for desmoid tumors. Its most common side effects included diarrhea, ovarian toxicity (harm to the ovaries), rash, nausea, and fatigue.
When to see a doctor
Pain, swelling, or trouble moving a part of your body can be symptoms of a desmoid tumor. A tumor in the abdomen can cause problems, such as blocking the intestines, so your doctor should watch its growth carefully. Call 911 or go to the emergency room for severe belly pain or pressure, or severe or persistent vomiting.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. Such a doctor can look at your symptoms and arrange imaging tests. They can also help you reach a sarcoma specialist and keep up with follow-up visits.
Common questions
Is a desmoid tumor cancer?
No, a desmoid tumor is generally not cancer, because it does not spread to other parts of the body. It can still invade nearby tissue and is often very painful.
Can a desmoid tumor go away on its own?
Yes, some do. In about 20 percent of cases, the tumors shrink or disappear with minimal or no treatment.
Does a desmoid tumor come back after surgery?
It can. The tumor often returns to the same place after surgery.
Do desmoid tumors run in families?
Most do not. In 5 to 10 percent of cases, desmoid tumors may run in families.
Is there an approved medicine for desmoid tumors?
Yes, the FDA approved nirogacestat (Ogsiveo) in November 2023 for adults with growing desmoid tumors who need treatment that works throughout the body. It was the first approved treatment for desmoid tumors.
Sources
- MedlinePlus Genetics - Desmoid tumor
- National Cancer Institute - Desmoid Tumor
- U.S. Food and Drug Administration - FDA approves nirogacestat for desmoid tumors
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
