What is chondroblastoma?

Chondroblastoma is a rare, benign bone tumor found in the rounded ends (epiphysis — secondary growth centers) of the long bones in the arms and legs.

It accounts for about 1 percent of all benign bone tumors and generally occurs in teenagers and young adults. It is slightly more common in males than females.


It is uncertain why chondroblastoma occurs, but it is sometimes found in conjunction with other growths, such aneurysmal bone cysts, which are found in 20-25 percent of all patients with chondroblastoma.

Signs and symptoms 

Symptoms of chondroblastoma usually occur in the shoulder, hip or knee and include:

  • Joint stiffness
  • Swelling
  • Pain that may be mistaken for a sports-related injury or trauma

Testing and diagnosis

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

  • X-rays, which produce images of bones.
  • Magnetic resonance imaging (MRI), which uses a combination of large magnets, radiofrequencies and a computer to produce detailed images of organs, soft tissues, muscles, ligaments and other structures within the body. Your child is exposed to no radiation during an MRI.
  • Computed tomography (CT) scan, which uses a combination of X-rays and computer technology to examine bones and produces cross-sectional images ("slices") of the body.
  • EOS imaging, an imaging technology that creates 3-dimensional models from two flat 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.
  • Needle biopsy, which is a procedure where a doctor places a small needle through the skin and into the lesion to withdraw a small sample of the abnormal tissue. The tissue is analyzed to confirm any findings.


There are many treatment options available for bone and soft tissue tumors, and some children will need a combination of these therapies. At CHOP, experts at the Bone and Soft Tissue Tumor Program take a team approach to treatment. Orthopaedic, cancer and other specialists collaborate to provide your child with individualized care and the best possible outcomes.

Our program is led by Kristy L. Weber, MD, and Alexandre Arkader, MD, nationally renowned surgeons who specialize in treating bone and soft tissues tumors, limb-sparing surgery and reconstructive surgery.

Surgery is the recommended treatment for all children with chondroblastoma.

Surgical treatment may include:

  • Intralesional curettage, which involves scraping out the bone to completely remove the tumor. When indicated, our surgeons will use minimally invasive techniques that preserve the adjacent growth plate (preventing long-term issues related to residual growth), and spare the joint space (limiting the risk of contamination and tumor spread).
  • Intraoperative adjuvants — such as cryotherapy (liquid nitrogen), phenol (a chemical) or cauterization (burning the tumor bed) — which are used to remove microscopic tumor cells
  • Bone grafting, a surgical procedure to replace missing bone with artificial graft material or cadaver bone

Depending on the size and location of chondroblastoma removed, your child may be able to return home that day or may spend one night in the Hospital.

Surgical safety

Though surgery for tumors 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. For more details about safety protocols at The Children's Hospital of Philadelphia, see safety in surgery.

Follow-up care 

There is a 10 percent risk of recurrence of chondroblastoma after treatment, so it is important for your child to continue to see his surgeon after treatment. There is a small — 1-2 percent — risk of chondroblastoma spreading to the lung.

Your child will see the orthopaedic surgeon about one to two weeks after surgery, then again every three to four months for two years to monitor for possible recurrence of the growth.

At Children's Hospital of Philadelphia (CHOP), we offer ongoing support and services for patients and families 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.

During follow-up visits, X-rays and other diagnostic testing of the tumor site are recommended to closely monitor your child’s health, check the reconstruction, and make sure there is no recurrence.

If the chondroblastoma returns, surgeons will treat the recurrence with intralesional curettage, intraoperative adjuvants, and bone grafting.

In most cases, a chondroblastoma will not recur more than two years after surgery.

If your child needs continued monitoring into adulthood, he can continue to see some of the same doctors who treated him. CHOP’s Bone and Soft Tissue Tumor Program works closely with Penn Medicine. For families who live farther away and need continued monitoring, our clinical professionals will help your child transition to adult care near home.

Reviewed by Alexandre Arkader, MD, Kristy L. Weber, MD, FACS

Providers Who Treat Chondroblastoma

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