Osteoid osteoma of the talus.

The talus is a rare site of predilection for osteoid osteoma. This tumor, in its juxta-articular position, presents particular clinical and pathological features. Three cases of subperiosteal osteoid osteoma are discussed in patients aged 15, 17 and 25 years. In diagnosis, a basic role is played by awareness of the disease, which must lead to the use of bone scan, indicating the site of the pathological lesion, which may be difficult to determine because of subtle radiographic modifications, and particularly because of long-term changes in the symptoms. Radiographic examination (standard x-rays, enlarged x-rays), often characterises and reinforces what is diagnostically suspected. CAT clearly shows the features and type of osteoid osteoma in relation to the adjacent structures. Sequential angioscintigraphy, based on the captation curve of the radionuclide, may suggest the nature of the lesion, subsequently confirmed by the macroscopic picture and histological examination.