Osteoid-osteoma: diagnostic problems.

The clinical records and roentgenograms of fifty-four patients had the typical features of osteoid-osteoma, but no histological evidence of a nidus was found at initial surgery. The symptoms of thirty-one patients were relieved by initial operation and those of twenty-three were not. In two cases, Brodie's abscess was identified in the surgical specimen. A second operation in eighteen patients brought relief in thirteen, and a nidus was found histologically in seven of these patients. A parosteal osteogenic sarcoma was found in one of the patients who had no relief of symptoms. Three patients underwent a third operation and were relieved of symptoms, a nidus being found in two. Thus, symptoms were relieved in thirty-six of forty-two patients in whom no nidus or other pathological entity was found, indicating the significance of this symptomatic sclerotic osseous lesion.