Osteofibrous Dysplasia (OFD)

Osteofibrous dysplasia (OFD), also known as ossifying fibroma of the long bones, is a very rare and benign type of bone tumour that occurs when osseous tissue (bone tissue) is replaced by fibrous tissue (tissue that makes up tendons and ligaments) in a bone. OFD is most commonly found in the bones of the lower legs (tibia and fibula), but can also be found in other bones such as the humerus (upper arm), radius (forearm), ulna (forearm), clavicle (collarbone), or mandible (jaw).

OFD is generally diagnosed equally among the sexes, and is most commonly found in children under 10 years old. However, anyone can develop this disease.

Treatment

When cancers are detected, they are staged and graded based on size, metastasis (whether the cancer has spread to other parts of the body), and how the cancer cells look under the microscope. Staging and grading helps your doctors determine the best treatment for you. However, as most OFDs are considered benign, these tumours are generally considered low-grade and not staged.

Once your tumour has been diagnosed, your doctor may recommend genetic testing, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. They will then discuss the most appropriate treatment option for you. Treatment is dependent on several factors, including location, age, stage of disease and overall health.

Treatment options for OFD may include:

  • Surgery, potentially including:
    • Surgical excision (minor surgical procedure to remove the cancer).
    • Curettage (cancer is scraped out with a small, sharp instrument called a curette).
    • Bone grafting (transplanting healthy bone tissue to repair and rebuild damaged bones).
    • Extraperiosteum resection (removal of affected bone portion. This is then treated with a bone graft or a prosthesis to fill the hole).
  • Bone brace (a stabilising device used to prevent limb bowing and further bone damage).
  • Clinical trials.
  • Palliative care.

For more information on the treatment options, please refer to the Rare Cancers Australia treatment options page.

Risk factors

Because of how rare OFD is, there has been limited research done into the risk factors of this disease.

Symptoms

Many patients with OFD appear asymptomatic in the early stages of disease. As the tumour progresses, some of the following symptoms may appear:

  • Pain and/or swelling in affected area.
  • Easily broken bones.
  • Limb bowing (when the legs curve outwards at the knees while the feet and ankles touch).

Not everyone with the symptoms above will have cancer, but see your general practitioner (GP) if you are concerned.

Diagnosis/diagnosing

If your doctor suspects you have an OFD, they may order the following tests to confirm the diagnosis and refer you to a specialist for treatment.

Physical examination

Your doctor will collect your overall medical history, as well as your current symptoms. Following this, they may examine your body to check for any abnormalities.

Imaging & blood tests

The doctor will take images of your body using magnetic resonance imaging (MRI), a computed tomography scan (CT scan), bone scan, and/or positron emission tomography (PET scan), depending on where it is suspected the cancer is. The doctor may also look at other parts of the body and looks for signs of metastasis. Additionally, a blood test may be taken to assess your overall health and help guide treatment decisions.

Biopsy

Once the location(s) of the cancer has been identified, the doctor will perform a biopsy to remove a section of tissue using a needle. The tissue sample will then be analysed for cancer cells. This can be done by a fine needle aspiration (FNA) or a core needle biopsy (CNB).

References

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