Scintigraphy in osteoid osteoma: problems related to differential diagnosis.

Scintigraphy is currently the most widely used and most reliable diagnostic instrumental test for the diagnosis of osteoid osteoma. Indications for its use are based on two considerations: 1) the need for preoperative confirmation of a suspected diagnosis based on clinical and radiographic findings; 2) the preoperative differential diagnosis from lesions which, either due to site or to atypical features, can mimic osteoid osteoma and are not easily identified. However, the high sensitivity of the test is associated with low specificity. In order to increase the specificity, the authors use angioscintigraphy and illustrate some cases where this method permitted differential diagnosis with other bone lesions that simulate the clinical and radiographic features of osteoid osteoma.