Fibrous dysplasia involving the base of the skull.

717 ibrous dysplasia is a developmental anomaly that can affect any bone in the body. The skull and facial bones are the affected sites in 10–25% of patients with monostotic fibrous dysplasia and in 50% of patients with polyostotic fibrous dysplasia. Conventional radiographic findings reveal characteristics of fibrous dysplasia. CT findings also show characteristics of fibrous dysplasia and consist of the following three varieties: the ground-glass pattern (56%), the homogeneously dense pattern (23%), and the cystic variety (21%) [1]. Unfortunately, the MR imaging characteristics of fibrous dysplasia do not share the distinctive features seen on radiography and CT. In fact, the MR imaging appearances of fibrous dysplasia often resemble that of tumors. The intent of this pictorial essay is to highlight the MR imaging features of fibrous dysplasia involving the base of the skull. An awareness of this potential diagnostic Fibrous Dysplasia Involving the Base of the Skull