Section 5. Bone, Joint, and Muscle Disorders

Chapter 63. Bone Tumors

Topics: Introduction | Noncancerous Bone Tumors | Primary Cancerous Bone Tumors | Metastatic Bone Tumors

Noncancerous Bone Tumors

Osteochondromas (osteocartilaginous exostoses), the most common type of noncancerous bone tumors, usually occur in people aged 10 to 20 years. These tumors are growths on the surface of a bone, which protrude as hard lumps. A person may have one or several tumors. The tendency to develop several tumors may run in families.

At some point in their lives, about 10% of the people who have more than one osteochondroma develop a cancerous bone tumor called a chondrosarcoma (presumably formed from an existing osteochondroma); surgical removal is generally appropriate if one of the tumors enlarges or causes new symptoms. Such people should also 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 problems, such as increased swelling.

Chondromas, which usually occur in people aged 10 to 30 years, develop in the central part of a bone. These tumors often are discovered when x-rays are taken for other reasons and often can be diagnosed by their appearance on the x-ray. Some chondromas cause pain. If a chondroma does not cause pain, it does not have to be removed or treated. However, follow-up x-rays may be taken to monitor its size. If the tumor cannot be diagnosed with certainty on x-rays or if it causes pain, a biopsy may be needed, usually consisting of the entire tumor (excisional biopsy), to determine whether it is noncancerous or cancerous.

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. If untreated, these tumors may continue to grow and destroy bone; therefore, treatment consists of surgical removal. Occasionally, these tumors recur after surgery.

Chondromyxoid fibromas (chondromyxofibromas) are very rare tumors that occur in people younger than 30; they are usually located near the ends of long bones. Pain is the usual symptom. These tumors have a distinctive appearance on x-rays. Treatment consists of surgical removal, which usually provides a cure, although tumors sometimes recur.

Osteoid osteomas are very small tumors that commonly develop in people aged 20 to 40. They are most common in the arms or legs but can occur in any bone. They usually cause pain that worsens at night and is relieved by low doses of aspirin. Sometimes the muscles surrounding the tumor waste away (atrophy); this condition may improve after the tumor is removed. Bone scans using radioactive tracers help determine the exact location of the tumor. Sometimes the tumor is difficult to locate, and additional tests, such as CT, may be needed. Surgically removing the tumor is one way to eliminate the pain permanently. However, some people prefer to take aspirin indefinitely rather than undergo surgery. Another procedure is less invasive than surgery. In this procedure, a doctor inserts a needlelike probe into the tumor, using CT as guidance for placement. A radio frequency pulse is then applied to destroy the tumor. Apart from the pain, the prognosis is good.

Giant cell tumors usually occur in people in their 20s and 30s. These tumors most commonly originate in the ends of bones and may extend into adjacent tissue. They usually cause pain. Treatment depends on the tumor's size. A tumor can be surgically removed, and the hole can be filled with a bone graft or a synthetic bone cement to preserve the bone's structure. Occasionally, very extensive tumors may require removal of the affected segment of bone. About 10% of the tumors recur after surgery. These tumors rarely become cancerous.