[Fibrous dysplasia of the skull. Radiologic diagnosis]

The authors examined 11 patients with fibrous dysplasia of the skull pointing out its radiologic features and preferential sites. Conventional radiology, CT and MR imaging were used. As for conventional radiology, tangential scans which of great value to depict the most typical morphologic patterns. Lesions of the skull base were most frequent in the sphenoid (7 of 11 cases), where 5 of 7 exhibited a sclerotic pattern. Bone changes in the skull vault were: mixed (3 cases), pagetoid (2 cases), "ground glass" (1 case) and lytic (1 case): none of these cases was of the sclerotic type. A typical feature of vault lesions was the widening of diploic space associated with expansion of the outer bone and integrity of the inner bone. Radiologic findings, often associated with suggestive clinical manifestations, always allowed a diagnostic hypothesis; histopathologic confirmation was needed only in a few cases (4 of 11 patients).