Noncancerous Bone Tumors
(See also Overview of Bone Tumors.)
Noncancerous (benign) bone tumors may be painless, but often they cause bone pain. The pain can be severe. Pain may occur when at rest or at night and tends to progressively worsen.
Chondroblastomas are rare tumors that grow in the ends of bones. They usually occur in people aged 10 to 20 years. These tumors may cause pain, leading to their discovery.
To diagnose a chondroblastoma, doctors take x-rays and may do other imaging tests, such as magnetic resonance imaging (MRI).
If untreated, these tumors may continue to grow and destroy bone and the joint. Therefore, treatment consists of surgical removal and use of a bone graft (transplantation of bone tissue from one bone to another) to fill in the defect. Graft material can be bone removed from the person’s own pelvis (autograft), processed bone tissue from another person (allograft), or a synthetic bone substitute. Occasionally, these tumors return after surgery.
Chondromyxofibromas are very rare tumors that usually occur in people younger than 30. They are usually located off to one side near the ends of the bones in the extremities (the limbs). Pain is the usual symptom.
To diagnose chondromyxofibromas, doctors take x-rays.
Treatment of chondromyxofibromas consists of surgical removal, which usually provides a cure. However, these tumors sometimes return.
Enchondromas may occur at any age but tend to develop in people aged 10 to 40 years. These tumors develop in the central part of a bone (the marrow cavity) in long bones.
These tumors usually do not cause symptoms, but some may grow larger and cause pain.
The tumors often are discovered when x-rays are taken for other reasons, and doctors often can diagnose them by their appearance on the x-ray.
If the tumor cannot be identified with certainty on x-rays or if it causes pain, removal of a tissue sample for examination under a microscope (biopsy) may be needed to confirm the diagnosis of enchondroma and rule out the possibility of a cancerous tumor.
If an enchondroma does not cause pain, it does not have to be removed or treated.
Enchondromas may change into a cancerous (malignant) bone tumor called a chondrosarcoma. This change is rare in people who have only a single enchondroma, but in people who have multiple enchondromas (called enchondromatosis), the change to a cancerous tumor is more common.
Follow-up x-rays may be taken to monitor any changes in size and make sure the tumor has not become a chondrosarcoma.
Fibrous dysplasia is abnormal bone development that occurs during childhood. It may affect one bone or several bones. The bones of the pelvis or hip are most frequently affected.
Children may have birth marks and signs of early puberty, which indicate a disorder called Albright syndrome (or McCune-Albright syndrome). The abnormal bone growths commonly stop developing at puberty. This condition rarely becomes cancerous (malignant).
This disorder is often found when x-rays are done for other reasons.
Bisphosphonates given by vein may help relieve the pain. A surgical procedure may correct deformities, fractures that do not heal when placed in a cast, or pain that cannot be relieved any other way.
Giant cell tumors usually occur in people in their 20s and 30s. These tumors most commonly start in the ends of bones and may extend into nearby tissue. They may cause pain.
Treatment of giant cell tumors depends on the tumor’s size. A tumor can be surgically removed, and the hole can be filled with bone graft, synthetic bone graft, or bone cement (methyl methacrylate) to preserve the bone’s structure. Occasionally, very extensive tumors may require removal of the affected segment of bone and reconstruction of the joint. One treatment is a surgical procedure called curettage, in which the tumor is scraped out with a scoop-shaped instrument. Then, before they fill the cavity, doctors may treat it with the chemical phenol or freeze it with liquid nitrogen. Some doctors heat the bone cement. These treatments help reduce the risk of the tumor returning. After this treatment, about 10% of tumors return. Giant cell tumors rarely become cancerous.
A nonossifying fibroma is an abnormality that results when part of a bone does not harden normally and instead is filled with fibrous tissue rather than bone tissue. A very small nonossifying fibroma is called a fibrous cortical defect. Nonossifying fibromas are common among children. They commonly occur close to the ends of the bones of the legs.
Most nonossifying fibromas eventually harden, sometimes more than normal bone. Small nonossifying fibromas do not cause symptoms. However, some small fibromas grow larger and may cause pain and increase the risk of a break (fracture).
Nonossifying fibromas are most often found when an x-ray is taken for another reason.
Small nonossifying fibromas require no treatment. However, fibromas that cause pain or have grown large are removed and a bone graft is done to fill in the defect.
Osteoblastomas are rare noncancerous tumors. Some doctors simply consider them to be large osteoid osteomas. Osteoblastomas are much more common among males and typically develop between ages 10 and 35. These tumors develop in the bones of the spine, legs, hands, and feet. They grow slowly and destroy normal bone and are painful.
To diagnose osteoblastomas, doctors take x-rays and do other imaging tests such as computed tomography (CT) and magnetic resonance imaging (MRI). To confirm the diagnosis of osteoblastoma, doctors remove a tissue sample for examination under a microscope (biopsy).
Treatment of osteoblastomas requires surgery. Often the tumors are removed and then bone grafting (transplantation of bone tissue from one bone to another) to fill in the defect is done. Sometimes the tumors return after surgery.
Osteochondromas (osteocartilaginous exostoses), the most common type of noncancerous bone tumors, usually develop in people aged 10 to 20 years. These tumors are growths on the surface of a bone, which stick out as hard lumps. A person may have one or several tumors. The tendency to develop several tumors can run in families.
At some point in their lives, about 10% of people who have more than one osteochondroma (called multiple osteochondromatosis) may develop a cancerous (malignant) bone tumor called a chondrosarcoma (presumably formed from an existing osteochondroma). People with multiple osteochondromatosis should visit their doctor for regular examinations. However, people who have only one osteochondroma are unlikely to develop a chondrosarcoma. Therefore, a single osteochondroma usually does not need to be removed unless it causes symptoms.
Doctors do x-rays to see the growths on the surface of the bone. Most osteochondromas are diagnosed by x-rays. Imaging tests, such as magnetic resonance imaging (MRI) or occasionally computed tomography (CT), are also done, especially if x-ray findings are unclear.
Surgical removal of an osteochondroma is typically done if it grows larger or causes new symptoms. For example, if the tumor disturbs growth of the bone, causes pain, or presses on nearby nerves, muscles, blood vessels, or surrounding structures, it should be removed.
Osteoid osteomas are very small tumors that commonly develop in people aged 10 to 35. They are most common in the long bones of the legs (the thighbones and shinbones) but can occur in any bone.
These tumors usually cause pain that worsens at night and is relieved by low doses of aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs). Sometimes the muscles surrounding the tumor waste away (atrophy) because the pain causes people to remain inactive. This condition may improve after the tumor is removed. If the tumor develops near the growth plate (the part of the bone from which growth occurs in children), bone growth can be overstimulated. This overstimulation can cause the limbs to grow to unequal sizes.
To diagnose osteoid osteomas, doctors take x-rays. Bone scans using radioactive tracers are also done to help determine the exact location of the tumor. Sometimes the tumor is difficult to locate, and additional tests, such as computed tomography (CT) or magnetic resonance imaging (MRI), may be needed.
To treat the tumor permanently, usually a doctor punctures the skin and inserts a needle-like probe into the tumor, using computed tomography as guidance for placement. A radiofrequency pulse, which heats the needle-like probe, is then applied to destroy the tumor. While this is done, the person is under general, spinal, or nerve block anesthesia. The prognosis is good, and pain should go away. Surgically removing the tumor is another way to eliminate the pain permanently. Alternatively, some people prefer to take pain relievers (analgesics) indefinitely rather than undergo a procedure. The pain may eventually go away without treatment.