label: fibrous dysplasia
label_lc: fibrous dysplasia
description: A genetic, non-inheritable disorder caused by osteoblastic differentiation defects that result in the replacement of bone marrow and trabecular bone by fibrous stroma and immature bone. It usually affects a single bone and less frequently multiple bones. Skull, femur, tibia, and humerus are the most frequently affected bones. It manifests with pain, deformities, and fractures.