What is Osteoblastoma?
Osteoblastoma is a benign, bone-forming tumor that is extremely rare, accounting for only 1 percent of all primary bone tumors. Unlike most primary bone tumors, which favor the extremities, osteoblastoma occurs most often in the lower vertebrae of the spine or long bones of the lower extremity. It can, however, also occur in any of the bones of the arms, legs, hands and feet. Most of the time, osteoblastoma is not aggressive, but it can produce painful symptoms. One form of this tumor is considered aggressive because it is very likely to recur after incomplete surgical removal. No reported osteoblastoma has transformed into a malignant condition. The aggressive form does not metastasize (spread) to other parts of the body.
What causes Osteoblastoma and who does it affect?
The exact cause of osteoblastoma is unknown. It typically occurs in the second decade of life, but patients range in age from about 5 years to 45 years. It affects males more than females at a ratio of 3:1.
What are the symptoms of Osteoblastoma?
The following are the most common symptoms of osteoblastoma. Keep in mind that each individual may experience symptoms differently:
- pain, usually increasing in severity with time
- atrophy of affected area
When osteoblastoma occurs in the spine:
- painful scoliosis
- muscle spasms
- limited range of motion
The symptoms of osteoblastoma may resemble other medical conditions. Always consult a physician for a diagnosis.
Osteoblastoma | Diagnosis & Treatments
How is Osteoblastoma diagnosed?
In addition to taking a complete medical history and performing a full physical examination, your child’s doctor may use some combination of the following tests to diagnose osteoblastoma:
- x-rays: a diagnostic test that uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film.
- computerized tomography scan (also called CT or CAT scan): a diagnostic imaging procedure that uses a combination of x-rays and computer technology to produce cross-sectional images (often called slices) both horizontally and vertically, of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs. This test is particularly useful in identifying tumors in areas that are difficult to image on a x-ray, especially the spine.
- magnetic resonance imaging (MRI): a diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body.
- bone scan: a nuclear imaging method to evaluate any degenerative and/or arthritic changes in the joints; to detect bone diseases and tumors; to determine the cause of bone pain or inflammation.
- complete blood count (CBC): a measurement of size, number, and maturity of different blood cells in a specific volume of blood.
How is Osteoblastoma treated at Boston Children’s Hospital?
Specific treatment for osteoblastoma will be determined by your child's physician based on:
- your child’s age, overall health, and medical history
- extent of the disease
- location of the tumor
- your child’s tolerance for specific medications, procedures, or therapies
- how your child’s physician expects the disease may progress
- your opinion or preference
Treatment for osteoblastoma usually involves an operation to remove the tumor performed by an orthopaedic surgeon. In some cases, if the tumor cannot be completely removed, adjuvant therapies described below may be used. The following surgical procedures are among those used to treat osteoblastoma:
- En bloc resection: If more aggressive resection of the tumor is warranted, the operation will likely involve en bloc resection, which is the surgical removal of bone containing the tumor. Internal fixation, with pins, may be required to restore the structural integrity of the bone.
- Curettage/Bone Grafting: Curettage describes a surgical scraping of the cyst with a special instrument called a curette that has a scoop, loop, or ring at its tip. This procedure may be opted for if the tumor cannot be removed by excision. Sometimes, the remaining cavity is then packed with donor bone tissue (allograft), bone chips taken from another bone (autograft), or other materials depending on the preference of the surgeon.
- Biopsy: During the operation, doctors will take a tissue sample of the tumor so the diagnosis can be confirmed under a microscope.
What is the long-term outlook for a patient with Osteoblastoma?
Prognosis for osteoblastoma is generally excellent, although prognosis varies from individual to individual depending on:
- how active the tumor is
- the tumor’s response to therapy
- the age and overall health of your child
- your child’s tolerance for specific medication, procedures, or therapies.
Most of these tumors can be successfully treated. However, recurrence can occur. Continuous follow-up care is essential for the successful treatment of an osteoblastoma. A schedule of follow-up care should be determined by your child's physician and other members of your care team to monitor ongoing response to treatment and possible late effects of treatment.