12. Fibrous dysplasia.cdr

Introduction: Fibrous dysplasias (FD) are a group of nonhereditary benign pathologies in which immature bone and fibrous stroma replace normal medullary bone as a result of abnormal differentiation of osteoblasts characterized by solitary (monostotic) or multi focal medullary (polyostotic) fibro osseous lesions. They contain mutated fibroblast cells and osteoblasts of varying functionality, which produce abnormally immature woven bone [1]. They are accounted for 2.5% of all the bone tumors and 5–7% of all benign bone tumors [2]. The detailed description as a benign developmental disorder of the bone was given by Lichtenstein and Jaffe in 1942 and thus it is referred as Lichtenstein-Jaffe disease [3]. The dormancy of FD increases from childhood to adulthood, however there is a life time risk of malignant transformation that of around 1–4% [4].