Endochondroma

  • What is endochondroma?

    Endochondromas are benign tumors made up of cartilage that form in the central area of the bone where bone marrow is stored. Cartilage is the tough, elastic, fibrous connective tissue that coats the bones where the joints are located. If your child has many endochondromas, he may be diagnosed with a syndrome called Ollier’s disease. Most endochondromas form in the hands and feet.

    There are two types of chondromas:

    • Endochondroma, which forms in the central area of the bone where red and yellow bone marrow is stored
    • Periosteal chondroma, which forms on the surface of the bone in what is called the periosteum — the fibrous membrane made up of numerous blood vessels and connective tissue that covers the bone

    Chondromas affect males and females equally between the age of 10 and 30.

  • Causes

    The cause of single endochondromas is unknown, but research has shown that Ollier’s disease has a genetic component. Multiple endochondromas are caused by a gene error that results in abnormal endochondral bone formation.

  • Signs and symptoms

    Endochondromas are usually painless and are usually found accidently for a non-related injury. Endochondroma of the hands and feet is suspected when fingers become enlarged, or fractures or deformities occur.

    If pain is a symptom — whether generalized pain or when bones are at rest — this can indicate a malignant tumor. Your child’s doctor should perform tests to determine if the tumor is the benign endochondroma or chondrosarcoma (a cancerous growth).

  • Testing and diagnosis

    At The Children’s Hospital of Philadelphia, our clinical experts use a variety of diagnostic tests to diagnose endochondroma in your child, including:

    • Radioisotope bone scan, which can help locate an area of abnormal bone growth.
    • Magnetic resonance imaging (MRI), which uses a combination of large magnets, radiofrequencies and a computer to produce detailed images of organs and structures within the body.
    • Computed tomography (CT) scan, which uses a combination of X-rays and computer technology to produce cross-sectional images ("slices") of the body.
    • X-rays, which produce images of bones and internal organs on film.
    • EOS imaging, an imaging technology that creates 3-dimensional models from two planar images. Unlike a CT scan, EOS images are taken while the child is in an upright or standing position, enabling improved diagnosis due to weight-bearing positioning.
  • Treatments

    Most endochondromas require no treatment.

    However, if the endochondroma gets larger or if it becomes painful, then doctors may recommend that your child get a biopsy of the affected bone to rule out a cancerous growth. A biopsy is a surgical procedure where a sample of the growth is removed and tested for malignant and benign cells.

    If surgery is necessary, intralesional curettage is generally the chosen treatment. Curettage involves scraping out the bone to completely remove the tumor and filling the space with material such as methyl methacrylate cement or diluted phenol. Bone grafting with removal is common.

    Though surgery for endochondroma is highly effective, we understand that any surgery can be a stressful experience for children and families. At CHOP, we offer a wealth of resources about how to prepare your child for surgery and what to expect during surgery.

    Additionally, we employ numerous best practices before, during and after surgery to decrease the risk of infection and increase positive outcomes. Safety in surgery is a top priority at Children’s Hospital.

  • Follow-up care

    Because endochondromas have the potential to become malignant chondrosarcomas, it is important for your child to see a physician regularly, especially if any symptoms recur.

    During follow-up visits, X-rays and other diagnostic testing may be done to monitor your child’s health.

    Follow-up care and ongoing support and services are available at our Main Campus and throughout our CHOP Care Network. Our team is committed to partnering with parents and referring physicians to provide the most current, comprehensive and specialized care possible for your child.

  • Outlook

    Most often endochondromas are found accidentally, during an examination for another condition. It is rare that they change and become malignant. Overall, 1 percent of endochondromas become malignant.

    In 30 percent of patients with Ollier’s disease, endochondromas will become malignant and form cancerous growths called chondrosarcomas.

    Prognosis for a single benign endochondroma is excellent. Research is ongoing to identify or isolate chemical markers that could differentiate between benign and malignant tumors.

Reviewed by John P. Dormans, MD, FACS on May 19, 2014