OBJECTIVE: To identify chest radiography findings suggestive of type 1 neurofibromatosis, establishing their frequency and evaluating the possibility of including the presence of posterior mediastinal masses as a criterion for the diagnosis of type 1 neurofibromatosis. MATERIALS AND METHODS: The present study included 141 patients with type 1 neurofibromatosis assisted at the Service of Radiology of Hospital de Base and Faculdade de Medicina de São José do Rio Preto, SP, Brazil, and submitted to standard chest radiography in postero-anterior and lateral views. The results were analyzed by non-parametric methods and the level of statistical significance was set at 0.05 (p = 0.05). RESULTS: The most frequent findings were the following: ribs erosion (19.8%), pectus excavatum (12.0%), kyphoscoliosis (3.5%) and posterior mediastinal masses (7.1%). Such results suggest that posterior mediastinal masses (neurofibroma and meningocele) should be included as a diagnostic criterion of type 1 neurofibromatosis, in conjunction with dysplasia of the sphenoid wing, pseudoarthrosis and thinning of long bone cortex, as defined by the National Institutes of Health. CONCLUSION: The presence of posterior mediastinal masses in association with the typical bone changes defined by the National Institutes of Health is a consistent finding to be considered as a diagnostic criterion of the disease.

Keywords: Type 1 neurofibromatosis, Radiology, Chest radiography, Bone abnormalities, Mediastinal neoplasms

Neurofibromatosis type 1 is one of the most common genetic diseases with autosomic dominant inheritance pattern in humans. The main radiological findings are: scoliosis, kyphoscoliosis, bone erosions, abnormal osseous growth, pseudarthrosis, meningeal cysts, deformity of the posterior wall of the vertebral bodies ("scalloping"), pectus excavatum, osteolytic lesions in the long bones and central nervous system abnormalities. The authors present the statistical data from the analysis of the radiological findings in 82 patients with neurofibromatosis type 1 attending the "Centro de Pesquisa e Atendimento em Neurofibromatose", in São José do Rio Preto, SP, Brazil, a multidisciplinary center for the study and treatment of neurofibromatosis.

Keywords: Neurofibromatosis, Neurofibromatosis type 1, Radiology, Phacomatosis