Malignant schwannoma of the sciatic nerve originating in a spinal plexiform neurofibroma associated with neurofibromatosis type 1--case report.
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A 26-year-old man with neurofibromatosis type 1 (NF1) presented with a giant malignant schwannoma of the sciatic nerve. The differential diagnosis of malignant peripheral nerve sheath tumor (MPNST) was based on clinical, radiological, and histological evidence. The tumor apparently originated in a spinal plexiform neurofibroma. The lesion was resected totally without neural damage to the sciatic nerve. However, the tumor recurred within 2 months. The patient died of unknown factors probably associated with the spinal involvement. MPNST associated with NF1 has a poor prognosis due to recurrence or metastasis despite complete macroscopic removal. (+info)
Intrathoracic malignant peripheral nerve sheath tumor in von Recklinghausen's disease.
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Malignant peripheral nerve sheath tumor (MPNST) is defined as any malignant tumor arising from or differentiating toward the cells of the peripheral nerve sheath. MPNST accounts for about 5-10% of all soft tissue tumors and is often associated with neurofibromatosis type I (NF-1, von Recklinghausen's disease). It is one of the malignant tumors associated with von Recklinghausen's disease. Its common site is the lower and upper extremities, trunk, head and neck. But intrathoracic manifestations are very rare. We report a case of a 40 year-old man with multiple neurofibromatosis who was presented with an intrathoracic malignant peripheral nerve sheath tumor. (+info)
A homozygous germ-line mutation in the human MSH2 gene predisposes to hematological malignancy and multiple cafe-au-lait spots.
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Individuals with a germ-line mutation in one of the DNA mismatch repair (MMR) genes are at significant risk for colorectal cancer and other tumors. Three families have previously been reported with individuals homozygous for mutations in the MMR gene MLH1 that are predicted to compromise MMR. These individuals develop hematological malignancies and/or neurofibromatosis type 1 at an early age. Here, in an individual, we demonstrate that a homozygous novel mutation in the MMR gene MSH2 is associated with leukemia and multiple cafe-au-lait spots, a feature of neurofibromatosis type 1. Because the hematological malignancies observed in the individuals homozygous for the loss of MMR are reflective of the lymphomas seen in mice lacking MMR, the mice may provide a useful model for human neoplasia. (+info)
Corkscrew retinal vessels in neurofibromatosis type 1: report of 12 cases.
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AIM: To describe a distinctive spectrum of retinal microvascular abnormalities in 12 patients with neurofibromatosis type 1 (NF-1). METHODS: This is an observational prospective study of the ocular fundus evaluated by direct ophthalmoscopy with or without fluorescein angiography, to investigate retinal microvascular abnormalities in 32 patients with NF-1 and in 30 control subjects. The evaluation included a complete general and neurological physical examination and in some cases computed tomography, magnetic resonance imaging with gadolinium-DTPA, or both. RESULTS: The occurrence of a distinctive spectrum of retinal microvascular abnormalities is described in 12 patients with NF-1 (37.5%). At the lower end of the spectrum, present in 10 patients, the anomaly consisted of minuscule second or third order tortuous venules, which were called "corkscrew retinal vessels." These were usually isolated but in a few cases multiple. They flow towards the superior or inferior temporal veins. They had a length of one to two disc diameters. They ended either in a minute tuft or vanished on the retinal surface. The upper end of the spectrum was seen in only two patients. One of them had an exceptionally large venous anastomosis on the nasal retina and the other had an arteriovenous malformation extending over one retinal quadrant. None of the patients in the control group had such retinal microvascular abnormalities. CONCLUSION: The "corkscrew" retinal vessels described in this report constitute a broad spectrum of microvascular markers in NF-1 patients. (+info)
Epidural haematoma after dural puncture in a parturient with neurofibromatosis.
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A case of epidural analgesia in a parturient with neurofibromatosis (von Recklinghausen's disease) complicated by dural puncture and epidural haematoma is described and the management of the case is discussed. The case emphasizes the need for antenatal assessment of parturients with neurofibromatosis in order that the necessary investigations can be arranged and informed consent for analgesia and anaesthesia can be obtained. (+info)
International consensus statement on malignant peripheral nerve sheath tumors in neurofibromatosis.
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Neurofibromatosis 1 (NF1) is an autosomal dominant tumor predisposition syndrome in which affected individuals have a greatly increased risk of developing malignant peripheral nerve sheath tumors (MPNSTs). These cancers are difficult to detect and have a poor prognosis. Because patients may present to specialists from widely differing disciplines, the association with NF1 is often not appreciated, and there is no cohesive pattern of care. A multidisciplinary group of 33 clinicians and scientists with specialist knowledge in MPNST and NF1 reviewed the current published and unpublished data in this field, and distilled their collective experience to produce a consensus summary on MPNST in NF1. The known clinical, pathological, and genetic information on MPNST in NF1was collated, and a database was established to record information in a uniform manner. Subgroups with a higher risk of developing MPNSTwere identified within the NF1 population. The consortium formulated proposals and guidelines for clinical and pathological diagnosis, surgical management, and medical treatment of MPNST in individuals with NF1.A multidisciplinary team approach to the management of this complex disorder is advocated. Progress can be made by adopting the guidelines proposed by this consortium and by widespread dissemination of standardized information. Collaborative research should be promoted with the aim of harnessing advances in molecular genetics to develop targeted therapies for MPNST in people with NF1. (+info)
Neurofibromin and NF1 gene analysis in composite pheochromocytoma and tumors associated with von Recklinghausen's disease.
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Composite tumor of pheochromocytoma and neuroblastoma, or ganglioneuroma, or ganglioneuroblastoma (composite pheochromocytoma), also known as mixed neuroendocrine and neural tumor, are sometimes combined with neurofibromatosis type 1 (NF1). To better understand the relationship between NF1 and composite pheochromocytoma, an immunohistochemical study using anti-neuro-fibromin that is an NF1 gene product and DNA sequence of NF1 Exon 31 were carried out in five cases of composite pheochromocytoma and in various tumors from five patients with NF1. Neurofibromin was not expressed in Schwann cells and sustentacular cells of composite pheochromocytomas and was very weakly or negatively expressed in neurofibroma of NF1 patients. However, it was strongly expressed in ganglionic cells and pheochromocytoma cells of the composite pheochromocytomas and also in mucosal ganglioneuromas, a gangliocytic paraganglioma, and in pheochromocytomas from the patients with NF1. Although there was no mutation in NF1 Exon 31, it could not be ruled out that there were mutations in other sites of the NF1 gene. Neurofibromin insufficiency may induce abnormal proliferation of Schwann cells in composite pheochromocytomas as well as in neurofibromatosis. (+info)
Comparative gene expression profile analysis of neurofibromatosis 1-associated and sporadic pilocytic astrocytomas.
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Pilocytic astrocytomas (PAs) are WHO grade I brain tumors that do not typically progress to more malignant grades of astrocytoma. Whereas there have been significant advances in the molecular genetics of high-grade astrocytomas, relatively little is known about the genetic changes associated with PA formation. In an effort to better characterize these low-grade neoplasms, we compared the gene expression profiles of six sporadic and two neurofibromatosis 1-associated PAs with other tissues and cell lines of both astrocytic and oligodendroglial origin. Hierarchical cluster analysis of gene expression data clearly delineated PAs from low-grade oligodendrogliomas and normal white matter. The two NF1-associated tumors and one of the sporadic PAs displayed expression profiles that were more closely related to those of cultured normal human fetal astrocytes. However, PAs also expressed individual genes typically associated with oligodendroglial lineage (e.g., proteolipid protein and PMP-22). The expression patterns of specific genes (e.g., ApoD) were unique to PA tumors, whereas genetic changes characteristic of high-grade astrocytomas were not encountered. Differential expression of two transcripts, neural cellular adhesion molecule and connexin-43, was confirmed at the protein level, suggesting that these cell adhesion molecules might be particularly important in the molecular pathogenesis of these tumors. We conclude that PAs are genetically unique gliomas with gene expression profiles that resemble those of fetal astrocytes and, to a lesser extent, oligodendroglial precursors. (+info)