Osteochondroma: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Osteochondroma?
An orthopedic surgeon, a doctor who treats bone and joint problems, usually manages an osteochondroma. An orthopaedic oncologist, a surgeon who treats bone tumors, may help if there are signs the tumor is changing. 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 an osteochondroma?
An osteochondroma is a benign tumor that develops during childhood or adolescence. Benign means it is not cancer. It does not spread to other parts of the body. The tumor is an abnormal growth on the surface of a bone, near the growth plate. Growth plates are areas of developing cartilage near the ends of long bones in children. The tumor is made of bone and cartilage, the smooth tissue that covers bone ends.
Solitary osteochondromas are thought to be the most common benign bone tumor. They make up 35 to 40% of all benign bone tumors. They are often found near joints such as the knee, hip, and shoulder. A person may have a single tumor or many tumors. Many tumors are called multiple hereditary exostosis, or MHE.
As a child grows, the tumor may grow too. Once a child has reached skeletal maturity, it typically stops growing.
Symptoms
Many solitary osteochondromas cause no symptoms. Symptoms may also show up long after the tumor forms. They are most often diagnosed in people aged 10 to 30. Possible symptoms include:
- A painless bump near a joint, most often at the knee or shoulder.
- Pain with activity, when a tendon snaps over the bony tumor.
- Numbness or tingling, when the tumor presses on a nerve.
- Loss of pulse or a change in the color of the limb, when it presses on a blood vessel. This is rare.
An injury can break the stalk of a tumor that has one. This causes immediate pain and swelling at the tumor. With MHE, people get firm, bony bumps around the knees, ankles, wrists, shoulders, and chest wall.
Causes and who gets it
The exact cause is unknown. A solitary osteochondroma does not result from injury. Males and females are equally likely to get one. Doctors think it is linked to a gene called EXT1, but it is not clear how a defect in this gene causes the tumors.
MHE is caused by changes in the EXT1 and EXT2 genes. About 90 percent of people with MHE inherit the gene change from one affected parent. In the rest, the change is new, and there is no family history. The tumors stop forming in the teenage years, when skeletal growth ends.
How doctors diagnose it
Many osteochondromas are found by accident, when an X-ray is done for another reason such as an injury. If you have symptoms, the doctor starts with a medical history and a physical exam. Then the doctor orders imaging tests. X-rays show the bony growth. CT or MRI scans give more detail, especially of soft tissues and the cartilage part of the tumor. A biopsy, which means taking a tissue sample, is usually not needed.
Treatment
In most cases of solitary osteochondroma, treatment is careful observation over time. The doctor may take regular X-rays to watch for changes. It is often wise to avoid resection, a procedure to remove part or all of a tumor, until the growth plate closes. This helps lower the chance that the tumor comes back.
The doctor may consider surgery if the tumor causes pain, presses on a nerve or blood vessel, or has a large cap of cartilage. The surgery is called excision. The surgeon removes all of the tumor and some surrounding tissue, at the level of the normal bone. How long it takes to return to daily activities depends on the tumor's size and location.
When to see a doctor
See a doctor about any new bump near a joint, or pain, numbness, or tingling near a known tumor. Sudden pain and swelling after an injury at the tumor can mean its stalk broke. Call 911 if a limb loses its pulse or changes color, or if you have sudden weakness or trouble breathing.
It is rare for an osteochondroma to turn into cancer, but it is possible. Signs include growth after puberty, pain at the site, and a cartilage cap thicker than 2 cm. If you notice a tumor growing after you or your child are done growing, get evaluated by an orthopaedic oncologist.
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 examine a bump, order an X-ray, and refer you to a bone specialist. They can also help keep track of the follow-up visits that observation requires.
Common questions
Is an osteochondroma cancer?
No. An osteochondroma is a benign tumor, which means it is not cancer. It is rare for one to change into cancer, but it is possible. With a solitary osteochondroma, the lifetime risk is less than 1%.
Does an osteochondroma always need surgery?
No. In most cases of solitary osteochondroma, treatment is careful observation over time. The doctor may consider surgery if the tumor causes pain, presses on a nerve or blood vessel, or has a large cap of cartilage.
Can an osteochondroma be prevented?
No. The cause of a solitary osteochondroma is unknown, so doctors have not found a way to prevent it. It does not result from injury.
Sources
- American Academy of Orthopaedic Surgeons (OrthoInfo) - Osteochondroma
- MedlinePlus Genetics - Hereditary multiple osteochondromas
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.
