Enchondroma

Bengin Tumors Within Bone Made of Cartilage Cells

bone health
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An enchondroma is a benign tumor found inside of bone. The typical scenario is that a patient had an x-ray for an injury to a joint, commonly the shoulder, knee, or ankle.  While the joint looks normal, an abnormality is seen inside the bone.  Often these are completely unrelated to the cause of pain, and one of the most common reasons is an enchondroma.

Benign Bone Tumors

When a patient hears they have a tumor, this can cause anxiety and fear; many patients are initially worried they have cancer.

  Benign bone tumors are noncancerous conditions, that do not spread to other locations.  While some benign bone tumors can cause problems, others often go unnoticed and don't have any impact on the patient's health.

The word benign is a word often used to describe tumors.  It means that a tumor is not aggressive and will not spread.  It is the opposite of the word malignant; a word used to describe tumors that are aggressive and can spread throughout the body.  Most tumors have characteristics of one or the other.  There are some slow-growing malignant tumors, and there are some locally aggressive benign tumors, but most fall into one of the two basic categories. 

Enchondromas

An enchondroma is a type of tumor that causes the formation of cartilage cells within a bone. Usually, these tumors occur in the hands or in the long bones of the extremities including the humerus (arm bone), femur (thigh bone) and tibia (shin bone).

The most common signs of an enchondroma include:

  • No symptoms whatsoever
  • Thickening of a finger with an enchondroma
  • Pain after an injury

As mentioned, most enchondromas behave without aggression.  There is a related condition where the tumor can be malignant, called a chondrosarcoma.  A low-grade chondrosarcoma (a malignant cancer) can behave like an enchondroma, and vice versa.

  If patients do have pain that is coming from the tumor, or if the x-rays have the appearance of a more aggressive problem, then a low-grade chondrosarcoma should be considered as a possible diagnosis.

There is a syndrome called Ollier's Disease in which patients have many enchondromas.  Patients with this condition are generally monitored more closely, as they are more likely to develop chondrosarcomas from what was previously an enchondroma.

Treatment and Monitoring

Typically, no treatment is necessary for an enchondroma.  Most abnormalities detected within bone can be rechecked with a normal x-rays over a period of time.  If the tumor looks like an enchondroma, stays the same or goes away, then there is generally no need for ongoing surveillance.  If the tumor starts to grow, shows signs of becoming more aggressive, it may be determined that the tumor needs to be treated more like a chondrosarcoma.  Unfortunately, biopsy results can be very difficult to distinguish between a normal enchondroma and a low-grade chondrosarcoma, therefore treatment decisions are generally based on symptoms and radiographic findings, rather than on biopsy results.

Within the hand, enchondromas can weaken the bone sufficiently that a fracture occurs.  When this happens, the injury is called a pathologic fracture.  The usual treatment of a pathologic fracture caused by an enchondroma in the hand is first to allow the broken bone to heal.  This may stimulate the enchondroma to heal as well.  If not, your surgeon may recommend a procedure to remove the tumor cells, and place bone graft in the bone the strengthen the bone and prevent re-injury.

Also Known As: Bone Island

Sources:

Marco RA, Gitelis S, Brebach GT, Healey JH."Cartilage tumors: evaluation and treatment" J Am Acad Orthop Surg. 2000 Sep-Oct;8(5):292-304.

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