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Genetic and Rare Diseases Information Center (GARD)

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Hereditary multiple osteochondromas

Other Names for this Disease
  • Hereditary multiple exostoses
  • Hereditary multiple exostosis
  • HMO
  • Multiple exostoses
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Your Question

I have multiple osteochondromas and experience severe pain in both of my legs. I have had surgery on my left leg, but still have pain in that leg. What can I do to solve this problem?

Our Answer

We have identified the following information that we hope you find helpful. If you still have questions, please contact us.

How might hereditary multiple osteochondromas (HMO) be treated?

Currently, there is no known medical treatment for HMO. Osteochondromas are not usually removed because they stop growing around age 12. Another consideration is how close the tumor is to the affected bone's growth plate, because surgery can affect how the bone grows.[1][2] Surgery may be considered, however, if an osteochondroma is causing pain, bone fracture, nerve irritation, or if the tumor continues to grow after the person's bones have stopped growing.[1][2] The surgical treatment of choice is complete removal of the tumor. Depending on the location of the osteochondroma, this may be relatively simple. However, if an osteochondroma is close to nerves and blood vessels, this may make surgery difficult and risky.[2]

Surgery may also be necessary to correct painful limb abnormalities that are caused by multiple osteochondromas. Surgery may be needed to cut and realign the bones that have become deformed, which is known as osteotomy.[2] If the legs are not equal in length, treatment may include a procedure to slow down the growth of the longer leg. Surgery may also be needed to correct the forearm deformity seen in this condition. Adults with this condition who have untreated forearm deformities usually do not have significant functional limitations.[1] Although rare, an osteochondroma can become cancerous (malignant), which usually takes the form of a low grade chondrosarcoma. This type of malignant tumor is unlikely to spread elsewhere in the body. Higher grades of cancer can occur, but this is even more uncommon. In that case, other therapies, such as chemotherapy and radiation, may be used in treatment.[1][2]

GeneReviews provides more information about treatment for hereditary multiple osteochondromas.
Last updated: 3/11/2011

What is the outlook for hereditary multiple osteochondromas (HMO)?

Prognosis and long-term survival can vary greatly from person to person. Generally, the prognosis for a person with HMO is favorable. Most often, osteochondromas stop growing at skeletal maturity.[2]

Most individuals with HMO have at least one surgery and many have multiple surgeries. Painful osteochondromas that do not affect the surrounding bone can simply be removed. Complete removal can help to avoid recurrence of the tumor and abnormal bone growth.[1] Osteochondromas that affect the surrounding bone, tissues, and/or nerves may be more difficult to remove and the outcome of surgery depends on the extent of the disease, the size and location of the tumor, and the tumor’s response to therapy. If an osteochondroma becomes a cancerous tumor (osteosarcoma), the outcome is also less certain. Prompt medical attention and aggressive therapy are important for the best prognosis. Continuous follow-up care is essential for a person diagnosed with multiple osteochondromas.[2]
Last updated: 3/11/2011