Paget's disease of bone

Paget's disease is a chronic disorder of the adult skeleton characterized by increased resorption and deposition of bone resulting in replacement of the normal matrix with a softened and enlarged bone. Initially, there is active resorption by large and increased numbers of osteoclasts containing multiple nuclei, followed by deposition of bone by numerous osteoblasts which most often results in a weakened disorganized bony structure that is interspersed with areas of fibrosis. Although localized to isolated areas of the skeleton, there may be widespread bony distribution.