Fibroxanthoma is one of the few commonly seen, non-aggressive bone lesions which are benign and asymptomatic in nature. This is the favored term for non-ossifying fibroma as its underlying pathologic findings are more precisely reflected. The fibrous proliferation begins at the cortex to the metaphysis of the long bone (thighbone and shinbone). This non-neoplastic process is more common in children and in men.
It is only discovered incidentally on x-ray that shows a single corticated lucent tumor in the posteromedial aspect of the distal femoral cortex. The fibrohistiocytic neoplasm possesses narrow, hardened margins that are scalloped and slightly expansile. While asymptomatic in character, when lesions are large enough, there would be microfractures and mild pain that may advance as pathologic fractures.