This type of cancer is prevalent in
children, and occurs 80% of the time around the knee joint
. However, at this point, the doctors aren't sure yet, since there are other conditions which may mimic osteosarcoma. Examples of such conditions include bone tuberculosis, and osteoma, a non-cancerous bone tumor. These other conditions have to be "excluded" by means of additional tests, before a diagnosis of osteosarcoma is finally arrived at.