Bone Lesions in Children with Neurofibromatosis

Neurofibromatosis is often related with severe orthopaedic disorders in children. Bone lesions are rare but pose severe difficulties in management. It affects the spine and long bones. Lesions are associated either from enlargement of neurofibromas that affect the normal growth or from primary neurofibromatosis of long bones. Dystrophic scoliosis appears with short curves, with kyphosis and rotation of the apical vertebrae. Usually affect the thoracic spine, with penciling of the ribs. Surgical treatment is challenging in cases of rapid progression. Scoliosis may appear with curvatures similar to those in idiopathic scoliosis, without dysplastic changes of the vertebrae. Anterior bowing of the tibia is manifestation of NF and is distinguished from the benign posterolateral bowing. Evaluation of the medullary canal and presence of cystic lesions in the tibia is essential. Progression to pseudoarthrosis or pathologic fracture is common. Surgical management of tibial pseudoarthrosis remains a difficult procedure. Pseudoarthrosis may appear in fibula, radius or ulna but are extremely rare. Irregular eccentric bone cysts in long bones that are commonly diagnosed after a pathologic fracture, must be differentiated for NF. Malignant transformation of neurofibromas must be considered when there is rapid progression of the lesion.