Fibrous and osteofibrous dysplasia of bone

Clinical features

Osteofibrous dysplasia is a benign fibro-osseous intracortical lesion that occurs almost exclusively in the tibia and fibula of children. There is an association with neurofibromatosis type 1. Congenital pseudoarthrosis of the tibia is thought to be a related lesion. Neurofibromin may play a role in the pathogenesis of osteofibrous dysplasia1.

Fibrous dysplasia is a benign fibro-osseous lesion which may occur in any bone. It is associated with Albright's syndrome. Mutation of the a subunit of the signal transducing G protein which stimulated cAMP formation is thought to underlie the pathogenesis.

Histopathology

Osteofibrous dysplasia is characterised by woven bone trabeculae with rimming of osteoblasts and a cellular proliferation of fibroblast-like cells. There is zonation, with peripheral trabeculae of lamellar bone and central trabeculae of woven bone

Fibrous dysplasia is characterised by slender curved trabeculae of bone devoid of osteoblastic rimming, within a cellular proliferation of fibroblast-like cells.

Immunohistochemistry

References

1Sakamoto, A., Oda, Y., Oshiro, Y., Tamiya, S., Iwamoto, Y., Tsuneyoshi, M. Immunoexpression of neurofibromin, S-100 protein, and leu-7 and mutation analysis of the NF1 gene at codon 1423 in osteofibrous dysplasia. Human Pathol 2002;32:1245-1251.

This page last revised 6.5.2002.

©SMUHT/PW Bishop