Adamantinoma is an extremely rare but highly aggressive form of cancer that usually occurs in the leg bones. Around 200 cases were documented between 1913 and 2011. Radiation and chemotherapy are generally ineffective, so doctors treat the disease by surgically removing the tumor.
Patients who suffer from this form of cancer usually experience pain and swelling in the affected limb. The bones might break easily, and the diseased leg might gradually become curved and misshapen. Lesions can form on the skin if the cancer spreads to the soft tissues. Most tumors are slow-growing, so some patients experience mild symptoms for several years before obtaining a diagnosis.
Around 60 percent of patients with adamantinoma previously experienced a broken bone or underwent some form of trauma to the affected limb. In 2011, doctors did not know the exact role that previous trauma played in the development of this form of cancer. Adamantinoma is most common in men who are between 20 and 30, but it can occur in individuals of any age.
Doctors classify adamantinoma tumors according to the age of the patient. Differentiated adamantinomas form in patients under 20, while classic adamantinomas occur in patients over 20 years old. Differentiated and classic adamantinomas differ from one another at the cellular level.
Although most tumors occur in the tibia, which is the larger of the two bones in the lower leg, tumors can form in other areas of the body as well. Some patients develop cancerous tumors on the jawbone, the humerus or metatarsus, and the spine, among other areas. The original tumor might also metastasize, or spread to other areas of the body.
Doctors diagnose this form of cancer by performing X-rays, computed tomography (CT) or magnetic resonance imaging (MRI) scans. Adamantinoma sometimes looks like other conditions, such as osteofibrous dysplasia — a disease that causes benign tumors to form on the tibia. A doctor might confirm the diagnosis by performing a biopsy.
This type of cancer does not respond to either radiation therapy or chemotherapy. Once a diagnosis has been made, doctors treat adamantinoma by surgically removing the tumor. Although doctors will attempt to spare the limb if possible, sometimes amputations are necessary to keep the tumor from recurring or spreading.
In 2011, approximately 85 percent of patients survived for 10 years after removal of the tumor. The cancer spread to other parts of the body in approximately 20 percent of patients, and recurred in around 19 percent of survivors 10 years after surgery. Patients whose tumors metastasized had a life expectancy of 12 years in 2011.
