What is an osteoid osteoma?
An osteoid osteoma is a noncancerous (benign) bone tumor. Each tumor usually measures less than 1 inch across. These tumors don’t grow or spread anywhere else in your body.
Osteoid osteomas most often develop in the long bones of your body. These long bones include your shin (tibia) and thigh (femur) bones. Osteoid osteomas may also form in your:
- Hands or fingers.
- Feet or ankles.
This condition usually causes aching, dull pain that worsens at night. Healthcare providers treat osteoid osteomas with non-steroidal inflammatory drugs (NSAIDs) or surgery.
Who might get an osteoid osteoma?
Osteoid osteomas usually form in people between the ages of 5 and 25. This condition affects three times as many men as women. But osteoid osteomas can affect anyone no matter their gender, ethnicity or race.
How common is an osteoid osteoma?
Osteoid osteomas make up about 10% of all benign bone tumors.
What is the difference between an osteoid osteoma and an osteoblastoma?
Osteoid osteomas and osteoblastomas are both types of benign bone tumors. But osteoblastomas differ in that they:
- Are larger than osteoid osteomas.
- Are usually found in the skull, ribs and backbone.
- Can reoccur more often.
- Don’t cause worse pain at night.
Symptoms and Causes
What causes an osteoid osteoma?
Researchers don’t know the exact cause of an osteoid osteoma. Causes of this benign bone tumor may include:
- Abnormal growth of cells in your body (neoplasia).
- Inflammation in your bone.
- Injury (trauma) to the area where the tumor occurs.
What are the symptoms of an osteoid osteoma?
The main symptom of an osteoid osteoma is achy, dull pain. This pain often gets worse at night. Activity has no effect on the pain.
Other symptoms may include:
- Bone deformity.
- Gait disorders.
- Joint pain and stiffness.
- Decrease in muscle size (atrophy).
- One leg being longer than the other (with a thigh or shin tumor).
- Sciatica and scoliosis (with a spine tumor).
Symptoms of a tumor near your joint may include:
Diagnosis and Tests
How is an osteoid osteoma diagnosed?
Your healthcare provider will first ask about your symptoms and do a physical examination. They may ask you questions about the pain, such as:
- How long you’ve had pain.
- How severe the pain is.
- What helps to relieve the pain.
- Whether you’ve had an injury to the painful area.
If your provider suspects an osteoid osteoma, they may suggest tests including:
X-ray: This diagnostic imaging test creates pictures of your bone. In an X-ray, an osteoid osteoma will appear as thickened bone that surrounds a small central core.
Three-phase bone scan: During a three-phase bone scan, your provider:
- Injects a radioactive material (radiotracer) into your vein. A camera detects this radiation and takes pictures of the radiotracer in your bone.
- The camera takes a picture of the blood that builds up in your bone and soft tissue.
- The camera takes another set of images of the same location two to three hours after the injection.
This scan helps your provider find the exact location of the tumor.
CT (computed tomography) scan or magnetic resonance imaging (MRI): A CT scan shows an image of your bone and can help identify an osteoid osteoma. An MRI is less accurate in showing an osteoid osteoma but can help rule out cancer.
Biopsy: During a biopsy, your provider removes a sample of the tumor. They look at this tissue under a microscope for signs of an osteoid osteoma. This biopsy also helps them to rule out other conditions.
Blood tests: Your provider may take blood tests to rule out an infection.
Management and Treatment
How is an osteoid osteoma treated?
Osteoid osteomas may go away on their own. But these tumors may not disappear for years.
You can treat an osteoid osteoma with NSAIDs. NSAIDs can be nonprescription (aspirin, ibuprofen or naproxen) or prescription. NSAIDs help to relieve pain and may speed shrinkage of the osteoid osteoma. With this conservative treatment, symptoms usually end within 33 months (2.75 years).
Providers may suggest surgery to treat an osteoid osteoma. You will be asleep under general anesthesia or the area will be numb (regional anesthesia) during the surgery. The types of surgery include:
Curettage: During curettage, your surgeon removes the entire tumor. Your surgeon reaches the tumor through a cut in your skin.
CT-guided radiofrequency ablation: During minimally invasive radiofrequency ablation, your surgeon removes the tumor by heating it. Your surgeon will:
- Use a CT scan to find the area of the tumor.
- Insert a radiofrequency probe into the tumor.
- Use a high-frequency electrical current to destroy the tumor by heating it.
Usually, you need only one radiofrequency ablation treatment to remove the tumor.
How can I reduce my risk of an osteoid osteoma?
You can’t reduce your risk of an osteoid osteoma. But you can look for the signs, so you can get prompt monitoring and treatment if needed.
Outlook / Prognosis
What can I expect if I have an osteoid osteoma?
What you can expect depends on what treatment you have.
Curettage: While curettage has a high success rate, complications may include:
- Damage to other tissues.
- Exercise limitations.
- Risks of general anesthesia.
- Weakened bone.
CT-guided radiofrequency ablation: This procedure has a 90% success rate. But complications may include:
- Complex regional pain syndrome (CRPS).
- Skin burns.
- Superficial thrombophlebitis.
When can I go back to work/school?
If you have curettage, you may need to stay in the hospital for a few days. After that, you may have physical therapy at home for several weeks before going back to work or school.
If you have radiofrequency ablation, you can usually go home that day. Most people can return to work or school in two or three days.
What is the outlook if I have osteoid osteoma?
The outlook is very good. Osteoid osteoma can go away completely either with time, NSAIDs or surgery.
How do I take care of myself with osteoid osteoma?
You can help to reduce complications after surgery if you:
- Limit exercise for a few months.
- See a physical therapist.
- Visit your provider immediately if you continue to have any pain.
A note from Cleveland Clinic
Osteoid osteoma is a noncancerous bone tumor. This tumor forms in your body’s long bones. Symptoms include pain that worsens at night, swelling and stiffness. Healthcare providers diagnose osteoid osteomas with X-rays and three-phase bone scans. Providers treat osteoid osteomas with non-steroidal inflammatory drugs (NSAIDs) or surgery. Osteoid osteomas can go away on their own over time or with treatment.
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