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.

A Case of Spinal Cord Compression Caused by Rhabdomyosarcoma of the Mediastinum Associated with Type I Neurofibromatosis(NF Type I)

A 12-years-old female admitted to the hospital with the complaint of pain on the right upper chest area which persisted about 1 month prior to admission. Cafe-au-lait spots of various size laying on a whole body and freckling on the axilla were found on physical examination. A huge mass was found on the plain chest X-ray and on chest MRI. The mass encroached thoracic spine, posterior rib, back muscles, and then into the neural canal and compressed thoracic spinal cord. On the 5th day of hospitalization, the patient complained tingling on the both legs and 2 days later, monoparesis on the right leg. Open thoracotomy and decompressive laminectomy was done to remove mass. Pathologic reports confirmed rhabdomyosarcoma, embryonal type.

Extracellular Matrix, TGF - beta Gene and Ha-ras Oncogene Expression in Type I Neurofibromatosis / 대한피부과학회지

BACKGROUND: Neurofibroma, the hallmark of neurofibromatosis, is a cutaneous or subcutaneous lesion, with a variable clinical presentation. Histologically, neurofibroma consists of proliferation of nerve derived cellular elements, together with an abundant, collagenous extracellular matrix. Specifically, neurofibroma has been shown to contain 30-50% collagen in its matrix. Objective 5. METHODS: We examined the expression of extracellular matrix genes (collagen, fibronectin, laminin), TGF-b mRNA and Ha-ras oncogene mRNA by using Northern and slot-blot hybridization and immunoperoxidase stains. Result: In Northern blot analysis, Ha-ras and TGF-b genes revealed respectively, 8.8kb and 2. 5kb sized mRNA transcripts in neurofibroma. These parameters were normal in the control. The expression of these genes were 1.9, 2.0 fold increased in neurofibroma. In slot-blot analysis, expression of type I collagen showed fibronectin genes to be 2,401+210, 540+43, respectively, in neurofibroma. So there were 3.7 fold, 2.1 fold, differences respectively, compared to the normal control. However, there were no significant changes of type IV collagen and laminin Bl mRNA levels between neurofibroma and normal skin tissues. Irnmunoperoxidase staining by rnonoclonal anti type IV collagen antibody in neurofibroma showed type IV collagen to be diffusely and weakly stained in tissue. On staining by monoclonal anti-laminin antibody, laminin was stained in a matrix and around vessels. CONCLUSION: The increased expression of extracellular matrix genes may suggest that there is a subpopulation of fibroic cells in neurofibroma which are stimulated by TGF-b. Ha-ras genes which might have accumulated with the differentiation of neural tissue may be related to the pathogenesis of neurofibroma tissue formation. Further studies are needed to determine whether the other factors are related to the pathogenesis of neurofibroma.

Malignant Schwannoma of the Scalp in Type I Neurofibromatosis: Case Report

It has been reported that malignant transformation of neurofibroma occurs in about 5 to 10 per cent of type I neurofibromatosis patients. This 68 year old female patient presented with a huge fungating mass lesion in the right parietal scalp, which had recently grown rapidly. She had multiple neurofibromas of varying sizes on the entire trunk, extremities, and face. On the basis of family history and opthalomologic examination, type I neurofibromatosis was diagnosed. The mass was totally removed and the pathologic report revealed malignant transformation of the benign neurofibroma to malignant schwannoma. According to the literature, the incidence of head and neck sarcomas is very low, in particular malignant schwannoma occurring in the scalp is extremely rare. This case was, then, a rare event associated with type I neurofibromatosis.