Unusual Radiologic Presentation of Monostotic Fibrous Dysplasia

Fibrous dysplasia, first described in 1938 by Lichtenstein,1 is a benign fibro-osseous lesion that can occur as an isolated skeletal lesion (monostotic form) or affect multiple skeletal sites (polyostotic form). In addition, fibrous dysplasia may be associated with single or multiple endocrinopathies, or with precocious puberty and cutaneous hyperpigmentation in McCune-Albright syndrome.2

Fibrous dysplasia usually appears as a well-defined radiolucent medullary lesion that is irregular and mildly expansive, with a hazy opacity classically described as having a “ground-glass” appearance. In the long tubular bones, fibrous dysplasia may cause expansion of the bone contour with cortical thinning and endosteal scalloping. The shaft typically is involved, but the metaphysis also may be affected. These changes usually are recognizable on plain radiographs, but in cases in which the lesion is difficult to visualize, computed tomography (CT) may be beneficial.

source: Ortho Supersite