summary Neurofibromatosis is an autosomal dominant disorder caused by a mutation in the NF1 gene that codes for the neurofibromin protein that typically presents with skin lesions, lower and upper extremity deformities, and spinal involvement. Diagnosis is made with the NIH Consensus Development Conference Statement criteria with the presence of a combination of cafe-au-lait spots, neurofibromas, freckling in axillary/inguinal region, optic glioma, lisch nodules, and the presence of a 1st degree relative with NF-1. Treatment depends on presence and severity of forearm, lower extremity or spinal deformity. Epidemiology Incidence 1:3,000 births for NF1 Anatomic location extremity deformities login to view 2 more bullets spine involvement login to view 2 more bullets Etiology Genetics autosomal dominant (AD) mutation in NF1 gene on chromosome 17q11.2 login to view 5 more bullets neurofibromatosis is the most common genetic disorder caused by a new mutation of a single gene Associated conditions scoliosis anterolateral bowing of tibia bowing of forearm bones with obliteration of medullary cavity login to view 2 more bullets neoplasias Diagnosis Diagnostic criteria according to the NIH Consensus Development Conference Statement (1987) the diagnostic criteria for NF-1 are met in an individual if two or more of the following are found login to view 7 more bullets Classification NF1 (von Recklinghaussen disease) most common NF2 associated with bilateral vestibular schwannomas Segmental NF features of NF1 but involving a single body segment Presentation General Presentation often presents with anterolateral bowing of tibia often presents with radial bowing Physical exam verrucous hyperplasia hemihypertrophy cafe-au-lait spots axillary freckling scoliosis anterolateral bowing or pseudoarthrosis of tibia dermal Plexiform-type neurofibroma may be seen Lisch nodules login to view 1 more bullet Neoplasias (Neurofibromatosis) Neurofibromas (plexiform-type) is pathognomonic for NF1 present in 4% of NF1 may be dermal or in deep tissues often associated with limb overgrowth Inoperable tumors may be treated with selumetinib can undergo malignant transformation to neurofibrosarcoma Wilms Tumor Scoliosis (Neurofibromatosis) Introduction spine is most common site of skeletal involvement in NF-1 login to view 1 more bullet can take two forms login to view 6 more bullets Imaging radiographs show login to view 3 more bullets MRI login to view 2 more bullets Treatment nonoperative login to view 3 more bullets operative login to view 8 more bullets Anterolateral Tibial Bowing (Neurofibromatosis) Introduction epidemiology login to view 3 more bullets pathophysiology login to view 1 more bullet differentials for tibia bowing login to view 8 more bullets Imaging radiographs login to view 1 more bullet Treatment nonoperative login to view 5 more bullets operative login to view 7 more bullets Techniques intramedullary nailing with bone grafting login to view 6 more bullets free fibular graft login to view 2 more bullets Prognosis Studies show between 8-10 years of decreased life expectancy compared to general population High incidence of malignancy and hypertension