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.