Polyostotic Fibrous Dysplasia

There are multiple, well-defined, "bubbly lesions," in the pelvis and proximal femora.
There is coxa vara deformity of the Rt. femur, where several lucent lesions can also be identified.
- You may be able to appreciate the smokey, "ground glass" appearance of the lesions.
- Intramedullary (IM) rod is present in the right femur.
$linear fractures$ Linear fractures are present in the right femur.
- The distal end of the IM rod is almost protruding from the femoral shaft.
Radiographic findings are compatible with Polyostotic Fibrous Dysplasia.

You may wish to review some facts regarding Fibrous Dysplasia:

Due to a failure of osteoblast maturation.
Unknown cause, not hereditary, one bone to multiple bone involvement.
M = F.
Mc-Cune Albright syndrome: Polyostotic,cutaneous pigmentation, endocrine dysfunction (e.g., precocious sexual development.
- Other endocrinopathies including hyperthyroidism, Cushing's disease, acromegaly, hyperparathyroidism, etc.
70-80% of cases are mono-ostotic -- e.g., rib (most common benign lesion there), femur, tibia, mandible, calvarium, humerus.
- Poly-ostotic more likely to involve skull, facial bones, pelvis, spine, shoulder.
serum alk. phos. may be elevated.
In tubular bones, expansile, with ground glass appearance.
In femur, coxa vara ("shepherd's crook") deformity may be present.
- Involvement of iliac bones is accompanied by involvement of prox. femur.
Poly-ostotic more severe and presents earlier than mono-ostotic.
- Both usually become quiescent at puberty.
- May reactivate with estrogen Rx, pregnancy.

Case courtesy Dr. J. Kalowitz, Dept. Radiology, SUNY HSCB.

Ref: Resnick, D., Bone and Joint Imaging, W.B. Saunders, Philadelphia, PA, 1989, pp. 1227-1231.