Prevalência de neurofibromas plexiformes em crianças e adolescentes com neurofibromatose tipo 1 / Prevalence of plexiform neurofibroma in children and adolescents with type i neurofibromatosis

OBJETIVO: Avaliar a prevalência de neurofibroma plexiforme em crianças e adolescentes com neurofibromatose tipo 1 e seu potencial de transformação maligna. MÉTODOS: Estudo retrospectivo realizado através da análise do banco de dados do Centro Nacional de Neurofibromatose, coletado nos seguintes serviços de referência entre 1996 e 2004: Instituto de Dermatologia Prof. Rubem David Azulay da Santa Casa de Misericórdia do Rio de Janeiro, Instituto de Pediatria e Puericultura Martagão Gesteira da Universidade Federal do Rio de Janeiro e Departamento de Imunologia e Microbiologia da Faculdade de Medicina de Teresópolis. RESULTADOS: Nesse período, foram atendidos 104 pacientes com idade de 1 a 17 anos e diagnóstico clínico de neurofibromatose tipo 1, sendo 53 do sexo masculino e 51 do sexo feminino. Destes, 28 pacientes (15 masculinos e 13 femininos) apresentaram neurofibroma plexiforme (26,9 por cento). Divididos por faixa etária, observou-se 21,42 por cento (seis) entre 1 e 5 anos; 35,71 por cento (10) entre 6 e 12 anos e 42,85 por cento (12) entre 13 e 17 anos. Dos 104 pacientes estudados, dois evoluíram para tumor maligno da bainha do nervo periférico (1,92 por cento). CONCLUSÕES: Os neurofibromas plexiformes são manifestações relativamente comuns em pacientes com neurofibromatose tipo 1 e podem ser causa de aumento significativo da morbimortalidade entre os pacientes. Concluímos, em nosso estudo, que a freqüência de neurofibroma plexiforme e de seu potencial de malignização na população observada está em conformidade com dados da literatura internacional.

OBJECTIVE: To assess prevalence of plexiform neurofibroma in children and adolescents with type I neurofibromatosis and its malignant potential. METHODS: A retrospective study was conducted through analysis of the database at Centro Nacional de Neurofibromatose [Brazilian Neurofibromatosis Center], collected from the following reference services between 1996 and 2004: Instituto de Dermatologia Prof. Rubem David Azulay da Santa Casa de Misericórdia do Rio de Janeiro, Instituto de Pediatria e Puericultura Martagão Gesteira da Universidade Federal do Rio de Janeiro and Department of Immunology and Microbiology at Faculdade de Medicina de Teresópolis. RESULTS: Over that period, 104 patients aged between 1-17 years were admitted with clinical diagnosis of type I neurofibromatosis. Of these, 53 were male and 51 were female, and 28 patients (15 male and 13 female) had plexiform neurofibroma (26.9 percent). Division by age group resulted in 21.42 percent (six) between 1-5 years; 35.71 percent (10) between 6-12 years and 42.85 percent (12) between 13-17 years. Of the 104 patients, two developed a malignant peripheral nerve sheath tumor (1.92 percent). CONCLUSIONS: Plexiform neurofibromas are relatively common manifestations in patients with type I neurofibromatosis and may be a cause of significant increase in morbidity and mortality among patients. In this study, we conclude that frequency of plexiform neurofibroma and its malignant potential in the population studied is in agreement with data from the international literature.

High frequencies of plexiform neurofibromas, mental retardation, learning difficulties, and scoliosis in Brazilian patients with neurofibromatosis type 1

A clinical study of Brazilian patients with neurofibromatosis type 1 (NF1) was performed in a multidisciplinary Neurofibromatosis Program called CEPAN (Center of Research and Service in Neurofibromatosis). Among 55 patients (60 percent females, 40 percent males) who met the NIH criteria for the diagnosis of NF1, 98 percent had more than six café-au-lait patches, 94.5 percent had axillary freckling, 45 percent had inguinal freckling, and 87.5 percent had Lisch nodules. Cutaneous neurofibromas were observed in 96 percent, and 40 percent presented plexiform neurofibromas. A positive family history of NF1 was found in 60 percent, and mental retardation occurred in 35 percent. Some degree of scoliosis was noted in 49 percent, 51 percent had macrocephaly, 40 percent had short stature, 76 percent had learning difficulties, and 2 percent had optic gliomas. Unexpectedly high frequencies of plexiform neurofibromas, mental retardation, learning difficulties, and scoliosis were observed, probably reflecting the detailed clinical analysis methods adopted by the Neurofibromatosis Program. These same patients were screened for mutations in the GAP-related domain/GRD (exons 20-27a) by single-strand conformation polymorphism. Four different mutations (Q1189X, 3525-3526delAA, E1356G, c.4111-1G>A) and four polymorphisms (c.3315-27G>A, V1146I, V1317A, c.4514+11C>G) were identified. These data were recently published.