Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at June 21, 2016

An enchondroma is a cyst comprised of cartilage that is located in bone. While these cysts usually appear on a simple X-ray, they can also be diagnosed through an MRI or a PET scan.


Definition & Facts

Enchondroma is a benign bone tumor that stems from cartilage, most often affecting the cartilage lining the inside of the bones. It is an overgrowth of this cartilage that can lead to further health problems or may not lead to any problems at all depending on the patient. The small, long bones in the hands and feet are the most common areas to have an enchondroma, but it can also happen in larger bones such as the humerus, femur, and tibia.

Enchondromas can occur at any age, but most commonly happen during adulthood. Enchondromas equally affect men and women. While typically painless, the tumor can involve a large portion of a bone, which may cause the cortical bone (compound bone that forms the outer structure of the bone) to thin. This can cause the bone to become weak which can lead to spontaneous bone fractures. When these tumors form in the small toe bones, they can result in pain similar to an ingrown toenail.

Symptoms & Complaints

Symptoms of enchondromas vary significantly, and many patients do not experience any symptoms at all. The most common symptoms of an enchondroma include slow bone growth in the area of the tumor, pain if the enchondroma is large, weakened bones, or enlargement of the affected area. These symptoms may be indications of several other medical conditions, so it is important to be seen by a doctor in order to get a proper diagnosis.

If the tumors become large in the hands or feet, the bones can become deformed. This can then lead to bone fractures. In patients who have a certain type of enchondroma resulting from Ollier disease or Maffucci syndrome, the bone deformities typically become very severe. Experiencing pain through the night or while resting is an indicator that the tumor may be malignant. However, due to the fact that pain is a common symptom of many ailments, a doctor will need to do further investigation.


The exact cause of enchondromas is unknown. Like all bone tissue, enchondromas originate from a growth plate comprised of cartilage but, unlike normal tissue, they had never transformed into bone.

Diagnosis & Tests

A diagnosis of enchondroma will begin with a routine physical examination where the doctor will investigate whether there is an enlargement in the extremities and will also check for fractures of the hand or foot. In addition to gathering a medical history of the patient and performing the physical exam, other tests may include X-rays, radionuclide bone scans, an MRI, or a CT scan.

X-rays are simple tests that use invisible electromagnetic energy beams to generate images of tissues, organs, and bones on film. Radionuclide bone scans are a nuclear imaging method used to find arthritis or degeneration of the joints. It can also detect tumors and bone diseases to determine the root cause of pain or inflammation of the bone. This can help rule out fractures and infections.

Magnetic resonance imaging (MRI) uses large magnets, a computer, and radio frequencies to create very detailed images of structures within the body. This is done to rule out any possible associated irregularities of the nerves and spinal cord. A CT scan is an imaging methodology that uses computer technologies and X-rays to create images of the body. A CT scan is able to show very detailed images of the body, including muscles, bones, fat, as well as organs. These are much more detailed than X-rays.

Doctor may also order a bone scan, which involves a minimal amount of radioactive dye injected through an IV. Enchondromas are usually active on these scans because tumors cause an increased uptake of the dye in the bone. A biopsy may be done to confirm an enchondroma. Here, a patient undergoes local anesthesia to let the doctor get a tissue sample of the tumor to then be examined.

The aggressiveness of the tumor is determined by these imaging tests as well as the appearance of the tissue sample of the tumor under a microscope. Enchondromas have chunks of cartilage that are easily seen through a microscope. Cartilage is not typically found in the center of a bone, but if an enchondroma is present, there will appear an abnormal amount of cartilage.

Treatment & Therapy

Enchondromas typically do not require treatment. When treatment is recommended, it can take many different forms depending on the patient and how aggressive the tumor is. Nonsurgical treatments can be performed on people who have no symptoms, or it is possible to just wait and watch to measure any tumor growth. Typically, tumors that do not have symptoms are not removed.

Surgical treatment, however, could involve curettage, where the tumor is removed from the bone by scraping. This removes the entire tumor, and once an enchondroma is removed, it will most likely not return. A bone graft may also be performed to stabilize the bone if it has become brittle or is likely to break. More aggressive tumors that include destruction of the bone or a mass growing on the bone are typically chondrosarcomas, which are malignant tumors that need to be removed immediately and entirely.

Prevention & Prophylaxis

There are few effective measures to prevent enchondromas because it is unclear what causes them in the first place. However, early detection and diagnosis are crucial to treat the disease. As with the prevention of any illness or mitigation of symptoms should an illness arise, it is important to lead a healthy lifestyle, limiting consumption of alcohol and refraining from using tobacco products.

Eating a balanced and healthy diet with a lot of calcium helps to keep the bones strong, preventing them from fracturing or breaking due to becoming brittle. While enchondromas cannot be prevented entirely, living a healthy lifestyle can help to keep the body strong overall, which may assist in recovery should one develop enchondromas.