Chondroblastoma is a rare tumor that accounts for approximately one percent of all bone tumor cases in the United States. This type of tumor is usually benign, but requires treatment to avoid long-term effects. It typically originates at the ends of the long bones. Approximately 72 percent of chondroblastoma cases are seen in the bones in the lower half of the body, including the femur, knee and tibia. Other areas affected are the upper arm bones and shoulder area.

Chondroblastomas are predominately seen in patients under the age of 25, in bones that are still growing. Males are nearly twice as likely as females to have a chondroblastoma. Without treatment, this bone tumor can cause muscle deterioration and reduced joint mobility. Though benign, it can be aggressive, potentially reaching a large size with a prominent inflammatory reaction. Despite being benign, chondroblastomas have the potential to involve multiple bones or to metastasize to the lungs.

Anatomy of the long bone

The bone is a complex element of the body, which can be divided up into three sections consisting of the following:

  • Epiphysis – Found on the end of the bone, where spongy cancellous tissue is covered by the articular cartilage
  • Metaphysis – Area that contains the growth plate, responsible for rapid increase in length during childhood and adolescence
  • Diaphysis – Long part of the bone consisting of a strong outer tube (cortex) for support, and a soft central component, largely composed of bone marrow

The bone is one of the body’s most complicated components. Because of the multitude of functions performed by the skeletal system and how closely each bone interacts with other parts of the body, long bones in particular are susceptible to contracting diseases.


There is still an immense amount of research to be done on this rare disease, so the causes of chondroblastoma are still relatively unknown. Here are some of the basic known facts researchers have discovered so far:

  • Immature cell production – When chondroblasts occur, it is typically in younger bones that are still developing.
  • Trauma – Many times when the bone has been damaged or experienced significant trauma, some unforeseen complications may be encountered during recovery. In rare occasions, chondroblasts may occur while the bone is repairing itself, which some speculate can cause chondroblastoma.


Most patients experience pain in their bones prior to any of the more severe symptoms associated with this rare disease. However, everyone’s body reacts differently, so it is important to seek the help of a professional.

The following are some of the most common chondroblastoma symptoms:

  • Localized pain
  • Joint pain
  • Reduced joint mobility
  • Joint swelling
  • Swelling and tenderness at the end of long bones
  • Unexplained bone fractures

Chondroblastoma symptoms are also common in other bone diseases, making it difficult to diagnose. Consult your doctor to have X-rays and other tests done to determine the cause of your symptoms.


Types of chondroblastoma include the following:

  • Chondroblast – The chondroblastoma tumor is derived from chondroblasts. Chondroblasts are immature cartilage-forming cells. In chondroblastomas, they are unable to make normal cartilage.
  • Metastasis of chondroblastoma – Rarely, cells from a chondroblastoma can metastasize and spread to other areas of the body, most commonly the lungs. These cases indicate a particularly aggressive form of the disease.

The multidisciplinary team of musculoskeletal oncology experts at Northwell Health Orthopaedic Institute treats chondroblastoma as well as a broad range of conditions that affect the bones.

(516) 321-7500

Make an appointment

Call now to find a Northwell Health Orthopaedic Institute physician.

Restoring Mobility

Ortho Institute

Northwell Health Orthopaedic Institute is dedicated to helping patients return to active, independent lives.