Congenital pseudoarthrosis of the limbs

A rare, genetic, non-syndromic limb malformation characterized by delayed union or non-union of a long bone, resulting in formation of a false joint, with abnormal mobility and angulation at the pseudoarthrosis site, which manifests with progressive anterolateral forearm or leg bowing, limb shortening, and non-healing fractures. Typical histopathological findings include fibromatosis-like proliferation in the soft tissues with cystic or dysplastic lesions. Neurofibromatosis and osteofibrous dysplasia are frequently associated.