Osteosarcoma

Alternative names:

osteogenetic sarcoma

Definition:

A malignant bone tumor, usually associated with the period of rapid growth seen in adolescence.

Causes, incidence, and risk factors:

Osteosarcoma is the most common bone tumor in children. The average age of diagnosis is 15 years old. Boys and girls have a similar incidence of this tumor until late adolescence at which time boys predominate.

The specific cause of osteosarcoma is not known. Evidence suggests that osteosarcoma can run in families. Associations with other diseases (many of which are hereditary) and recent advances in recombinant DNA technology have identified genes that indicate an increased risk. The gene involved in familial retinoblastoma appears to be a defective tumor inhibitor gene and is associated with other tumors including osteosarcoma.

Osteosarcoma tends to occur in the femur (distal end), humerus (proximal end) and tibia (proximal end). The end of the bone in which they occur is the area of greatest change and highest growth rate. Osteosarcoma can occur in any bone, however.

The most common symptom initially is pain. As the tumor grows, there may be visible swelling and limitation of motion. Tumors in the legs cause limping, while those in the arms cause pain on lifting. Swelling over the tumor may be warm and slightly reddened.