Fibrous dysplasia.

Skeletal fibrous dysplasia is a developmental anomaly in which normal bone marrow is replaced by fibroosseous tissue. This process may be localized to a single bone, or even a small segment thereof, or affect the skeleton diffusely. The radiologic archives of the Armed Forces Institute of Pathology (AFIP) contain 501 cases of histologically proved and radiographically correlated fibrous dysplasia (of which 427 cases are monostotic and 74 cases are polyostotic). We present the spectrum of radiologic findings, including those from bone scintigraphy, computed tomography, and magnetic resonance imaging, augmented where appropriate by accompanying pathologic material.