Benign Tumor Fundamentals
Fortunately, the majority of tumors that originate in the bones are benign, meaning that the tumor is very unlikely to spread from its original site to a new location.
Contrary to what most people expect, benign bone tumors occur most often in people less than 30 years old. Most are discovered in children, while their skeletons are still growing. These tumors are often strongly influenced by the hormones that stimulate normal growth. As a result, many benign tumors actually stop growing once a child reaches skeletal maturity (i.e. when bones stop growing in length). This usually occurs between the ages 14-16 in girls and the ages of 16-19 in boys.
Among the most common benign tumors involving bone are endochondroma, osteochondroma, nonossifying fibroma, chondroblastoma, osteoid osteoma, osteoblastoma, periosteal chondroma, giant cell tumor, and chondromyxoid fibroma. Some conditions such as aneurysmal bone cyst, unicameral bone cyst, and fibrous dysplasia are sometimes grouped with benign bone tumors. They often require similar treatment, but are not truly tumors.
Benign tumors can occur in any bone of the skeleton. Some types of tumors are most common in specific locations such as the spine or near the growth plates of the largest bones. In general, the most common bones involved are also the largest, the femur, tibia, humerus, and pelvis.
Some “benign” tumors occasionally are locally aggressive tumors that can progressively destroy bone. An example would be giant cell tumor of bone. This particular tumor would need early local management before the end of a bone is destroyed.
What are the symptoms?
A palpable lump or swelling can be the first sign of a benign tumor. However, the most common sign is persistent or increasing pain in the region of the tumor. Sometimes tumors are discovered only after a fracture occurs where the bone has been weakened by the growth of the tumor.
Pain associated with a bony lesion is cause for immediate concern.
What are my treatment options?
Treatment for benign bone tumors depends on the specific type of tumor, its size, its location, and age. Sometimes, surgery is not necessary. For example, some tumors will often resolve and heal after a fracture. Others may stop growing if the patient is near maturity at the time they are discovered. Some are discovered only by chance when an X-ray is taken for another reason such as an injury to a nearby area, and may only need to be observed for a period of time to insure that they are not growing or showing signs of being aggressive. Most often, however, surgery is necessary.
Surgical treatment includes both removing the tumor and the regeneration of new healthy bone at the site of the tumor. The surgeon caring for these tumors must have knowledge and experience with specialized techniques for removing these tumors with minimal trauma to surrounding normal tissues. He or she must also have broad knowledge and experience with techniques for bone grafting and skeletal regeneration, in order to provide young patients with the greatest possible chance of returning to full and unlimited activities following successful treatment. Most benign tumors respond very well to surgical removal. The likelihood that the tumor will come back is low, usually less than 5%.
Some tumors, such as osteoid osteoma, are frequently treated by radio frequency ablation or thermal necrosis. These procedures require anesthesia and are often done as a combined approach. Patient evaluation is accomplished before the orthopaedic surgeon and radiologist examination.
What are the risks of surgery?
Many times the surgery is very straightforward and includes a biopsy for the tissue to be studied under the microscope. Once confirmation is made of the diagnosis as a benign lesion, usually the lesion will be curetted (scraped out) and bone grafted. It is unusual to have major problems with this type of surgery. However, risks include nerve injury, infection, bleeding, and stiffness.