Fibro-Osseous Lesion: A Diagnostic Dilemma

Abstract

Fibro-osseous lesions of the craniofacial complex are represented by a variety of disease processes that are characterized by pathologic ossifications and calcifications in association with a hypercellular fibroblastic marrow element. They are a diverse group of processes that characterized by replacement of normal bone by fibrous tissue containing a newly formed mineralized product. The commonly included fibro-osseous lesions are fibrous dysplasia (FD), cemento-osseous dysplasia and ossifying fibroma. Ossifying fibroma is a true benign neoplasm, whereas Fibrous dysplasia is a genetic developmental anomaly of the bone-forming mesenchyme with a defect in osteoblastic differentiation and maturation that leads to a replacement of normal bony tissue by fibrous tissue of variable cellularity and immature woven bone. The main histologic differences between the two lesions lie in the absence of a capsule and the presence of more immature bone without osteoblastic activity in fibrous dysplasia. Cemento-osseous dysplasia is the most common fibro-osseous lesion affecting the jaw bones.