musculoskeletal and connective tissue disorders
Benign Bone Tumors and Cysts
Fibrous dysplasia
Fibrous dysplasia involves abnormal bone development during childhood. It weakens bone. Fibrous dysplasia may affect one or several bones. Multiple fibrous dysplasias, cutaneous pigmentation, and endocrine abnormalities may be present (Albright syndrome or McCune-Albright syndrome). The abnormal bone lesions of fibrous dysplasia commonly stop developing at puberty. They rarely undergo malignant degeneration. On x-ray, the lesions can appear cystic and may be extensive and deforming. On imaging, the lesions have a classic ground-glass appearance. Proximal femur lesions, because the bone is weakened, undergo plastic deformation, resulting in the appearance of a "shepherd's crook" deformity on x-ray. Bisphosphonates or RANKL inhibitors (eg,denosumab) may help relieve pain. Progressive deformities, fractures that do not heal with immobilization, or intractable pain may be effectively treated surgically. 