Neurofibromatosis最新文献

This paper is a summary review of recent developments with regard to the pathogenesis of von Recklinghausen neurofibromatosis, or NF-1. In the section on molecular biology of NF-1, the focus is on genetic linkage, with a note about prenatal diagnosis, tumor genetics and animal models. In the section on growth factors and receptors, the first element deals with neurofibromatosis as a model of cellular interaction, and particularly the issues of dysplasia versus neoplasia, cell-cell interactions and 'vicious cycle' positive feedback mechanisms; additional elements focus on nerve growth factor-beta, Schwann cell mitogens and other growth factors. In the last section, the focus is on further developments in terms of molecular biology, but with additional emphasis on the need for very intense input from the clinicians characterizing the many phenotypes of NF-1 and its NF and non-NF alternatives.

The literature is replete with suggestions that patients with neurofibromatosis (NF) in general and von Recklinghausen NF (NF-1) in specific often manifest mild mental retardation. However, intellectual performance in NF-1 has only rarely been the subject of study in a comparatively uniform population; it has been reported mainly in the setting of case histories. In the present material, representing a population-based cohort of Gothenburg, Sweden, it was possible to assess intelligence levels in 71 of the 74 patients originally identified [Samuelsson B, Samuelsson S: Neurofibromatosis 1989;2:6-22]. Thirty-two of the seventy-one patients (45%) showed slight mental retardation and 2 of these were somewhat more retarded than the remainder. This slight mental retardation was usually recognized during the early school years; it did not appear to be progressive. While patients affected with this problem were placed in remedial or special classes in school, these patients generally did not acquire any vocational training. There is reason to suspect that NF-1 itself leads to some impairment of intellectual development in all patients, for the intellectual achievements of those whose intelligence was judged to be within the normal range appeared to fall short of the average. Non of the patients with normal intelligence had passed any academic examination and many showed achievements less than expected based on the achievements of their healthy relatives. In certain families, the NF appeared to be associated with mild mental retardation more than in other families. Mental retardation of a more severe degree, corresponding to special school level or lower, is not typical of NF-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Neurofibromas contain fibroblasts and many mast cells, and recent hypotheses have linked fibrous tissue growth to activated mast cells. We describe the ultrastructure of mast cells and fibroblasts in a case of neurofibromatosis. Mast cells were numerous and showed extensive signs of activation. Mast cells were often intimately associated with fibroblasts, and mast cell granules could be seen inside fibroblasts ('transgranulation'). The fibroblasts were also activated. These results suggest that interactions between mast cells and fibroblasts may be important in the prominent collagen production that takes place in these tumors.

Neurofibrosarcoma (NFS), which is rare in the general population, occurs with excessive frequency among patients with von Recklinghausen neurofibromatosis (NF-1). Among 693 patients with NF-1 enrolled in the Baylor NF Program, 24 patients (3.5%) developed NFS or one of its variant forms. Nine of the twenty-four patients developed NFS within 3-94 months after enrolling in the Program for other reasons. Focus on these 9 patients alone suggests that the relative risk for patients with NF-1 developing NFS is 10-10,000 times greater than for the general population. Also, in NFS cohorts, patients with NF-1 are almost twice as likely to be under 30 years of age.

A point prevalence study of von Recklinghausen neurofibromatosis (NF-1) was undertaken in greater Dunedin, New Zealand, having a base population of 113,700. A total of 52 individuals with NF-1 were identified, for a crude prevalence estimate of 45.7 per 100,000 (95% confidence interval 31.6-59.8 per 100,000) or 1 in 2,190 and an age-standardized prevalence of 48.5 per 100,000 (95% confidence interval 34.7-62.4 per 100,000) or 1 in 2,062. This is the highest prevalence estimate reported to date. This is presumed most likely to be due to a small population effect. The prevalence of NF correlated with age, being greatest among those aged 20-29 years and relatively low among those 60 or more years of age.

We report on a discordant twin male with neurofibromatosis and manifestations of the Noonan syndrome. He has multiple café-au-lait spots and axillary freckling, relative macrocephaly, ptosis, mid-face hypoplasia, short neck and pulmonic stenosis. The presence of neurofibromatosis associated with Noonan syndrome phenotype in our patient raises the question of a unique disorder sharing characteristics of both conditions.

This report describes three cases from one surgical unit of the Mansoura Teaching Hospital of Cairo, Egypt, with generalized neurofibromatosis and associated breast lesions. Two patients had carcinoma of the breast and the third had cystosarcoma phylloides.

Areas of increased signal seen on magnetic resonance imaging (MRI) of the brain are frequently present in neurofibromatosis and are considered possible areas of dysplasia or heterotopias. Since Rosman and Pearce [Brain 1967; 90:829-838] have shown that neuronal heterotopias in deep cerebral white matter are associated with mental retardation in neurofibromatosis type 1 (NF-1), we hypothesized that these areas of increased signal seen on MRI should be associated with learning difficulties or incoordination in children with NF-1. Using MRI, we studied 31 children with NF-1 and attempted to correlate the presence of areas of increased signal with learning difficulties or incoordination. We found no association. This suggests that either these areas of increased signal are heterotopias which are not associated with learning difficulties or incoordination, or these areas of increased signal are not heterotopias and are not relevant to the study of learning problems or incoordination in children with NF-1.