What is an enchondroma?

An enchondroma is a type of noncancerous bone tumor that begins in cartilage. Cartilage is the connective tissue from which most bones develop. Cartilage plays an important role in the growth process. There are many different types of cartilage in the body. An enchondroma most often affects the cartilage that lines the inside of the bones. It often affects the long, tiny bones of the hands and feet. It may also affect other bones such as the thighbone (femur), upper arm bone (humerus), or one of the two lower leg bones (tibia).

An enchondroma may happen as one or several tumors. The health conditions that cause multiple tumors include:

• Ollier disease. This is when multiple areas in the body grow the tumors.

• Maffucci syndrome. This is a combination of multiple tumors and benign tumors made up of blood vessels (angiomas).

Enchondromas are the most common type of hand tumor. They may affect a person at any age but are most common in people ages 10 to 20. They affect men and women equally.

What causes an enchondroma?

The exact cause of enchondroma is not known. However, it is thought to happen due to either of the following:

• Overgrowth of the cartilage that lines the ends of the bones

• Ongoing growth of original, embryonic cartilage

What are the symptoms of an enchondroma?

With an enchondroma, you may have no symptoms at all. The following are the most common symptoms of an enchondroma. However, each person may experience symptoms differently. Symptoms may include:

• Hand pain, if the tumor is very large or if the affected bone has weakened and caused a hand fracture

• Enlargement of the affected finger

• Slow bone growth in the affected area

The symptoms of enchondroma may look like other medical problems. Always talk with your healthcare provider for a diagnosis.

How is an enchondroma diagnosed?

Diagnosis is sometimes made during a routine physical exam or if the tumor leads to a fracture.

The healthcare provider will ask about your medical history and give you a physical exam. You may also have tests. These tests may include:

• X-rays. This test uses invisible electromagnetic energy beams to make images of internal tissues, bones, and organs on film.

• Radionuclide bone scans.  This is a nuclear imaging test. It can show any degenerative or arthritic changes in the joints, find bone diseases and tumors, and find the cause of bone pain or inflammation. This test helps to rule out any infection or fractures.

• MRI. This test uses large magnets, radio waves, and a computer to make detailed images of organs and structures in the body. This test is done to rule out any problems of the spinal cord and nerves.

• CT scan. This is an imaging test that uses X-rays and a computer to make horizontal images of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs. CT scans are more detailed than general X-rays.

How is an enchondroma treated?

Treatment will depend on your symptoms, age, and general health. It will also depend on how severe the condition is.

Treatment may include:

• Surgery. In some cases, surgery is done when bone weakening is present or fractures occur.

• Bone grafting. This is a surgery where healthy bone is taken from another part of the body and transplanted into the affected area.

If there is no sign of bone weakening or growth of the tumor, your healthcare provider may simply keep a close watch on your condition. However, follow-up with repeat X-rays may be needed. Some types of enchondromas can develop into cancerous bone tumors later. Careful follow-up with your healthcare provider is often recommended.

Key points about enchondromas

• An enchondroma is a type of benign bone tumor that originates from cartilage. It is not cancerous. It most often affects the cartilage that lines the inside of the bones.

• Enchondromas are the most common type of hand tumor.

• The exact cause of enchondroma is not known.

• It is most common between ages 10 and 20.

• It affects women and men equally.

• You may have no symptoms at all.

• Diagnosis is sometimes made during a routine physical exam or if the presence of the tumor leads to a fracture.

• Treatment may include surgery, bone grafting, or watchful waiting.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

• Know the reason for your visit and what you want to happen.

• Before your visit, write down questions you want answered.

• Bring someone with you to help you ask questions and remember what your healthcare provider tells you.

• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your healthcare provider gives you.

• Know why a new medicine or treatment is prescribed and how it will help you. Also know what the side effects are.

• Ask if your condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if you do not take the medicine or have the test or procedure.

• If you have a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your healthcare provider if you have questions, especially after office hours and on weekends and holidays.