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[Spontaneous rupture of the flexor tendon of the hand disclosing the presence of Recklinghausen's disease].

Seemingly spontaneous subcutaneous ruptures of the flexor tendons of the hand are not frequently encountered. The case studied is that of a young man whose deep flexor tendon of the third finger snapped during a slight effort. The histological and immunohistochemical analysis led to the conclusion that there was localization of an intra-tendinous neurofibroma, which would seem to be a so-far undescribed phenomenon. The patient presented neurofibromas elsewhere and had pigmented spots on the body, which enabled Von Recklinghausen's disease to be diagnosed.

Adult↗

[Large bilateral lung opacities].

We report the case of a 42-year-old woman operated for neurofibroma of the scalp on two occasions who consulted for bilateral chest pain which reveated two voluminous bilateral pulmonary masses. Biopsy of one of these masses was in favor of secondary or primary leiomyosarcoma. The association of Von Recklinghausen's disease and soft tissue sarcoma is rare: most often neurofibroma which degenerates is observed. Other types of sarcoma, like leiomyosarcoma, have been described.

Adult↗

Unidentified bright objects associated with features of neurofibromatosis 1.

Unidentified bright objects are commonly observed on magnetic resonance imaging in young neurofibromatosis 1 patients, but their clinical and pathologic significance is largely unknown. Diagnostic features of neurofibromatosis 1 include café-au-lait spots, intertriginous freckling, Lisch nodules, neurofibromas, bony lesions, and optic glioma. We investigated the relationship between unidentified bright objects and other features of neurofibromatosis 1. Data from the National Neurofibromatosis Foundation International Database included 523 neurofibromatosis 1 patients between 2 and 20 years of age who had cranial magnetic resonance imaging examinations. The presence or absence of unidentified bright objects, diagnostic features of neurofibromatosis 1, and central nervous system neoplasms was known in these patients. Logistic regressive models were used to measure associations between unidentified bright objects and the other features while controlling for age. The occurrence of unidentified bright objects was associated with the number of diagnostic features, but most significantly with central nervous system neoplasms other than optic gliomas [odds ratio (OR) = 9.0, 95% confidence interval (CI) = 1.2-70], optic gliomas (OR = 2.1, 95% CI = 1.2-3.6), subcutaneous neurofibromas (OR = 2.0, 95% CI = 1.3-3.1), and Lisch nodules (OR = 1.6, 95% CI = 1.1-2.3). These findings suggest a common causal mechanism between unidentified bright objects and these cardinal clinical features in children with neurofibromatosis 1.

Adolescent↗

Neurofibromatosis type I presenting with urinary retention and lung collapse.

A 26-year-old male presented with urinary retention, spastic paraparesis and a swelling in the right side of the neck. Urinary retention was due to a neurofibroma of a lumbar spinal root compressing the urinary bladder and right ureter retroperitoneally. Paraparesis was due to an intraspinal neurofibroma causing cord compression at the cervicodorsal junction. In addition, this tumour was contiguous with the mass in the neck, and also with another large mass in the right hemithorax which was causing collapse of the right lung.

Adult↗

[Multiple peripheral nerve tumors: update and review of the literature].

Multiple tumours of the peripheral nerves are seen only in neurofibromatosis. They are hereditary. They present and develop in a variety of different ways. Three main groups are distinguished: von Recklinghausen neurofibromatosis or type 1; bilateral acoustic neurofibromatosis or type 2 and schwannomatosis recently defined as type 3. The aim of this study was to clarify the clinical outcome of neurofibromatosis. The diagnosis is made purely on clinical grounds. Cranial MRI and slit lamp examination are useful for classification. Surgical management for peripheral nerve tumours is similar. Any new and rapid change noted at clinical examination (increase in volume, pain or neurological deficit) requires surgery because of potential malignant transformation of the neurofibroma into neurofibrosarcoma (type 1 only). The definitive treatment depends on the resectable character of the tumour which is usually only known after epineurotomy under operating microscope. In the event of resectable tumour (schwannoma) enucleation must be performed, preserving nerve continuity. In the event of unresectable tumour (neurofibroma), tumour resection is impossible without sacrificing nerve tissue. An epineurotomy must be performed. It prevents further deterioration. Interfascicular biopsy confirms the histological type. Our results are similar to those in other recorded studies. The unpredictable clinical course of neurofibromatosis makes prolonged follow-up mandatory.

Aftercare↗

Neurofibromatosis in monozygotic twins: a case report.

A case report is given of a pair of monozygotic twin girls with neurofibromatosis caused by a new mutation. The symptomatology was dominated by a neurofibrosarcoma on the leg of one twin and by a large plexiform neurofibroma on the neck of the other twin. Otherwise, the disease showed similar, although not identical or mirror-image distribution of subcutaneous neurofibromas and café-au-lait spots. The twins had identical HLA and blood group antigens and the same chromosome aberration. These case reports indicate that nonhereditary factors may influence the manifestations of neurofibromatosis. A review of the literature on monozygotic twins with neurofibromatosis is given.

Adult↗

Otorhinolaryngological manifestations of von Recklinghausen's disease in Nigerians.

Otorhinolaryngological manifestations of 13 patients with von Recklinghausen's disease appearing at Lagos University Teaching Hospital over a five-year period have been studied. Among patients with ENT manifestations of the disease, the most common general features exhibited were cutaneous neurofibromas (100 per cent), headache (69.23 per cent) and pruritus (46.15 per cent). But the head and neck findings included external meatal canal stenosis (30.77 per cent), conductive deafness (30.77 per cent), nasal discharge (30.77 per cent), cranial nerve involvement (30.77 per cent) and disfigurement of the soft tissues of the face (30.77 per cent). Involvement of pinna (23.31 per cent), rhinolalia aperta (15.38 per cent), mental retardation (15.38 per cent) and pharyngeal swelling (7.69 per cent) also featured. Clinically detectable bilateral acoustic neurofibromas in adults or astrocytomas in children were not found in this series. Involvement of the frontoparietal bone (7.65 per cent) presented with skull bossing which had to be differentiated from that due to sickle cell disease in the African. There was also a singular case of phrenic nerve involvement. However, malignancy occurred in one (7.69 per cent) of these patients. Thus, it is important always to follow-up these patients closely so as to detect malignant transformation in time.

Adolescent↗

Neurofibromatosis type 1 in a pediatric population: Ste-Justine's experience.

BACKGROUND: To date, few pediatric series of neurofibromatosis type 1 (NF-1) have been described in the literature even though it is the most frequently encountered phakomatosis. METHODS: We reviewed 987 charts of pediatric patients with a presumptive diagnosis of NF-1 who were evaluated at Ste-Justine hospital from January 1, 1991 to July 31, 2002. Patients who presented with two or more cardinal criteria were diagnosed with NF-1. Clinical and laboratory data were retrospectively collected, including: demographics, neuroimaging and presence or absence of associated symptoms or signs of NF-1. RESULTS: A total of 279 patients were diagnosed with NF-1. The mean age at diagnosis was 3.4 years. Ninety-nine percent of the patients had café au lait spots and 47% had a first degree relative with NF-1. Almost 60 percent (59.6%) of those seen by an ophthalmologist had Lisch nodules. Optic glioma was found in in 14.7%, cutaneous neurofibromas in 38.4%, plexiform neurofibromas in 24.7%, neurofibrosarcoma in 1.8%, learning disabilities in 39%, attention deficit disorder in 40.5%, osseous dysplasias in 7.2%, pseudoarthrosis in 3.6%, precocious puberty in 3.2% and short stature in 17.9%. Magnetic resonance, when performed, showed hyperintense T2 lesions in 87.1% of cases. The mean period of follow-up was 7.4 years. CONCLUSION: Neurofibromatosis type 1 is a multisystemic disorder associated with increased risk of malignancy. It can be diagnosed at a very young age and clinical follow-up is advised. To our knowledge, this is the largest single center study of NF-1 in a pediatric population.

Adolescent↗

Integrated genomic analysis of NF1-associated peripheral nerve sheath tumors: an updated biorepository dataset.

Neurofibromatosis type 1 (NF1) is an inherited neurocutaneous condition that predisposes to the development of peripheral nerve sheath tumors (PNST) including cutaneous neurofibromas (CNF), plexiform neurofibromas (PNF), atypical neurofibromatous neoplasms of uncertain biologic potential (ANNUBP), and malignant peripheral nerve sheath tumors (MPNST). The Johns Hopkins NF1 biospecimen repository promotes the successful advancement of therapeutic developments for NF1-associated PNST through acquisition and genomic analysis of human tumor specimens. RNA sequencing (RNAseq) and whole exome sequencing (WES) data were generated from 73 and 114 primary human tumor samples, respectively. These pre-processed data, standardized for immediate computational analysis, are accessible through the NF Data Portal, allowing immediate interrogation. This dataset combines new and previously released samples, offering a comprehensive view of the entire cohort sequenced. As a dedicated effort to systematically bank tumor samples from people with NF1, in collaboration with molecular geneticists and computational biologists, the Johns Hopkins NF1 biospecimen repository offers access to tissue samples and genomic data to promote the advancement of NF1-related tumor biologic insights and therapies.

Humans↗

Notch and Schwann cell transformation.

Benign plexiform neurofibromas in NF1 patients can transform spontaneously into malignant peripheral nerve sheath tumors (MPNSTs). Although mutations in the p53 gene have been found in a subset of MPNSTs and mouse models support a role for p53 mutations in malignant conversion, we found that each of three Schwann cell lines derived from human MPNSTs possessed active p53. One of the lines expressed the Notch intracellular domain (NICD), indicative of ongoing Notch signaling. Consistent with a role in malignancy, NICD was able to transform primary rat Schwann cells. Transformation was robust--NICD-transduced cells generated tumors in nude rats--and was associated with the loss of markers associated with Schwann cell differentiation. These data suggest that aberrant Notch signaling may contribute to the conversion of benign neurofibromas to MPNSTs.

Animals↗

Activation of the neuregulin-1/ErbB signaling pathway promotes the proliferation of neoplastic Schwann cells in human malignant peripheral nerve sheath tumors.

Patients with neurofibromatosis type 1 develop aggressive Schwann cell neoplasms known as malignant peripheral nerve sheath tumors (MPNSTs). Although tumor suppressor gene mutations play an important role in MPNST pathogenesis, it is likely that dysregulated signaling by as yet unidentified growth factors also contributes to the formation of these sarcomas. To test the hypothesis that neuregulin-1 (NRG-1) growth factors promote mitogenesis in MPNSTs, we examined the expression and action of NRG-1 in human MPNSTs and neurofibromas, the benign precursor lesions from which MPNSTs arise. Multiple alpha and beta transmembrane precursors from the class II and III NRG-1 subfamilies are present in both tumor types. Neoplastic Schwann cells within these neoplasms variably express the erbB kinases mediating NRG-1 responses (erbB2, erbB3 and/or erbB4). Human MPNST cell lines (Mash-1, YST-1, NMS-2 and NMS-2PC cells) similarly coexpress multiple NRG-1 isoforms and erbB receptors. These MPNST lines are NRG-1 responsive and demonstrate constitutive erbB phosphorylation. Treatment with PD168393 and PD158780, two structurally and mechanistically distinct erbB inhibitors, abolishes erbB phosphorylation and reduces DNA synthesis in these lines. These findings suggest that autocrine and/or paracrine NRG-1/erbB signaling promotes neoplastic Schwann cell proliferation and may be an important therapeutic target in neurofibromas and MPNSTs.

Biomarkers↗

Clinical features associated with recurrence of tumours of the spinal cord and cauda equina.

STUDY DESIGN: Retrospective review of consecutive cases of recurrent spinal cord and cauda equina tumours. OBJECTIVES: We sought to identify factors and conditions resulting in re-operation to treat recurrences of spinal cord and cauda equina tumours. SETTING: Keio University Hospital, Tokyo, Japan. METHODS: Re-operation was performed in 39 patients with spinal cord and cauda equina tumours. Times of operation, interval between operations, affected spinal level, tumour site on cross section, configurations among dumb-bell tumours, and pathologic diagnoses were analysed. Recurrence rates were defined in terms of the number of cases with re-operation due to tumour recurrence relative to the total number of surgical cases for the same period at our institution. RESULTS: Recurrence rates were relatively high for intradural, extramedullary tumours and for tumours located anteriorly rather than laterally. Of patients with intradural, extramedullary plus extradural tumours who underwent initial surgery at our hospital, 75% (9/12) recurred; all tumours had dumb-bell-type configurations. The overall rate of re-operation due to tumour recurrence in 249 cases was 7.2% at our institution. By tumour types, 40% of malignant schwannomas recurred (2/5), as did 35.7% of neurofibromas (5/14), and 33.3% of ependymomas (6/18). CONCLUSION: Risk factors for tumour recurrence were anterior location, an intradural, extramedullary plus extradural site, extensive dumb-bell tumours, and pathologic diagnoses of neurofibroma, ependymoma, or malignant schwannoma.

Adolescent↗

Reduced expression of neurofibromin in the soft tissue tumours obtained from patients with neurofibromatosis type I.

1. We analysed the expression of neurofibromin mRNAs, encoded by the gene responsible for neurofibromatosis type 1, and of neurofibromin protein in nine soft tissue tumours by S1 nuclease mapping and Western blot analyses. Four tumours were obtained from patients with neurofibromatosis type 1, comprising two neurofibromas, one fibrolipoma and one malignant schwannoma, and five neurogenic tumours were obtained from non-neurofibromatosis type 1 patients. 2. All tumours, except for a malignant schwannoma, similarly expressed three species of mRNA encoding neurofibromin, an isoform with the insertion of 21 amino acids in the domain related to ras GTPase-activating protein, and an N-terminal isoform lacking this domain. 3. Western blot analysis demonstrated deficiency of neurofibromin in the tumours derived from three out of the four neurofibromatosis type 1 patients: a fibrolipoma, a malignant schwannoma and a neurofibroma. In contrast, reduction in neurofibromin was not detected in the five tumours obtained from non-neurofibromatosis type 1 patients. Furthermore, the expression of ras GTPase-activating protein was detected in all nine tumours examined. 4. The undetectable or reduced level of neurofibromin in the tumours obtained from neurofibromatosis type 1 patients suggests that this deficiency is closely related to their tumourigenesis.

Adult↗

Ossifying fibromyxoid tumor of soft parts: clinicopathologic, immunohistochemical and ultrastructural study of four cases.

Four cases of uncommon soft tissue tumors were investigated histopathologically. All of them consisted of fibrous and myxoid components, and mature bone showed shell-like characteristics. Histological features revealed these tumors were well circumscribed by a thick collagenous fibrous capsule and composed of uniform-sized fusiform cells with eosinophilic cytoplasm and a round or oval nucleus in the myxoid matrix. An incomplete shell of mature bone with lamellar structure was also observed at the periphery. Immunohistochemical and ultrastructural studies were performed. The major component of the proliferating cells in the tumors had positive staining for vimentin, S-100 protein, neuron-specific enolase and synaptophysin. The myxoid matrix was stained by alcian blue and was digested completely by pretreatment with hyaluronidase. Electron microscopy showed the cytoplasm contained dense-core granules measuring 100-200 nm and abundant filaments of an intermediate size. It is suggested that these uncommon tumors might be diagnosed as the 'ossifying fibromyxoid tumor of soft parts' previously described by Enzinger et al., which were derived from peripheral nerve sheath tumors such as neurofibroma and myxoid neurofibroma.

Adult↗

Aberrant cutaneous expression of the angiogenic factor midkine is associated with neurofibromatosis type-1.

Neurofibromatosis type 1 is a common autosomal dominant disorder (incidence 1:3500) characterized by lesions that include neural crest derivatives such as Schwann cells and melanocytes. A critical event in the pathogenesis of neurofibromatosis type 1 is the heterozygous germ-line loss of the tumor suppressor gene NF1. Additional genetic and/or epigenetic events have been posited, including various alterations in growth factor expression. By in situ hybridization and immunohistochemistry, we demonstrate aberrant expression of the angiogenic and tumorigenic growth factor midkine in the skin of patients with neurofibromatosis type 1, but not normal individuals. We demonstrate that midkine expression is independent of the presence of neurofibromas, and thus appears to be associated with mutations in the NF1 gene. Furthermore, midkine-containing culture media is shown to stimulate the growth of human endothelial and neurofibroma-derived cells. In conclusion, we introduce the skin as a source of dysregulated growth factors in neurofibromatosis type 1, and suggest the further study of the angiogenic factor midkine in neurofibromatosis type 1 pathogenesis.

Angiogenesis Inducing Agents↗

Intestinal neurofibromatosis is a subtype of familial GIST and results from a dominant activating mutation in PDGFRA.

BACKGROUND & AIMS: Intestinal neurofibromatosis (Online Mendelian inheritance in Man database number 162220) is an alternate form of neurofibromatosis. Patients present with neurofibromas limited to the intestine in the absence of any other typical features of NF1 and NF2. At present, the molecular basis of intestinal neurofibromatosis remains elusive. The aim of the present study was to find the gene responsible for intestinal neurofibromatosis and to characterize functionally the mutation. METHODS: Three candidate genes (NF1, KIT, and PDGFRA) were screened for mutations in 3 sisters diagnosed with intestinal neurofibromatosis. Five tumors were available for pathologic examination. Activation (phosphorylation) of PDGFRalpha was subsequently tested by Western blot analysis on a transfected 293T and Ba/F3 cell line. RESULTS: We found an inherited mutation (Y555C) in the juxtamembrane domain of PDGFRA in the affected individuals. The Y555C mutation leads to autophosphorylation and thus activation of PDGFRalpha. These observations confirm that PDGFRalpha(Y555C) is an oncogenic kinase. The clinical phenotype in the reported family resembles the syndrome of familial gastrointestinal stromal tumors (familial GIST). Somatic activating mutations in KIT and PDGFRA are frequent in sporadic GISTs, and mutations in both genes have also been described in familial GISTs. The tumors in the reported family are morphologically identical to intestinal neurofibromas, but, immunohistochemically, they do not express S100 or any of the known GIST markers. CONCLUSIONS: The inherited PDGFRA mutation in the reported family shows that intestinal neurofibromatosis is allelic to familial GIST caused by PDGRA mutations. We therefore propose that these tumors be classified as familial KIT-negative gastrointestinal stromal tumors.

Adult↗

The role of surgery in children with neurofibromatosis.

BACKGROUND/PURPOSE: Neurofibromatosis frequently is complicated by the development of symptomatic lesions such as optic gliomas and plexiform neurofibromas that require operative resection. Although characteristically benign, these neoplasms have often devastating functional and cosmetic effects and must be monitored for malignant transformation. The purpose of this study is to identify and describe the surgical considerations in the care of children with neurofibromatosis. METHODS: The authors reviewed the charts of all children (<21) at our institution with neurofibromatosis who underwent an operative procedure from 1979 to 1999. Patient demographics, symptomatic lesions, malignant transformation, form of surgical intervention, type of anesthesia, and outcome were collected. RESULTS: A total of 249 patients with either neurofibromatosis 1 or 2 were identified. Of these, 50 (20%) underwent a total of 93 operations. The average age at operation was 9.4 years (1.2 to 21 years). There were 40 soft tissue procedures, 21 intracranial, and 32 miscellaneous. The soft tissue masses typically were treated with wide local excision, and in 8 of these procedures multiple resections were performed. Fourteen of the 50 patients had malignancies. Five of the tumors were soft tissue sarcomas, and 9 were intracranial malignancies. Three patients died, 2 from malignancy and 1 from acute, obstructive hydrocephalus after operation. There were 3 patients alive with malignancy and 8 others living with varying levels of disability. CONCLUSIONS: Neurofibromatosis in the pediatric patient frequently requires surgical intervention, often because of symptoms such as pain or cosmetic deformity, or for malignancy. Children should be watched carefully for signs of malignant transformation and undergo biopsy for neurofibromas that exhibit rapid growth. Management of sarcomas should be aggressive with consideration given to re-excision, placement of brachytherapy catheters, metastectomy, and limb salvage with adjuvant therapy when possible. Preoperatively, children should receive clinical and radiographic (computed tomography or magnetic resonance imaging) evaluation for hydrocephalus.

Adolescent↗

[Neurofibromatosis versus schwannomatosis].

Neurofibromatosis Type 1 and 2 (NF1 und NF2) are different forms of neurofibromatosis, well defined both clinically and genetically. In absence of typical clinical features of NF1 (café-au-lait-spots, cutaneous neurofibromas, Lisch-nodules) or NF2 (vestibular schwanoma) clinical classification is often not possible. Neurofibromas are more common in NF1 and schwannomas are typical for NF2, but pathological histology does not provide sufficient evidence for diagnosis. We describe 14 patients who presented with the clinical picture of multiple spinal tumours. Detailed family history, exact clinical examination including an ophthalmological examination led to the diagnosis of NF2 in four cases. Mutation analysis confirmed the diagnosis of NF2 in one case by identification of a 163 base pair deletion in the NF2 transcript. To investigate the expression of schwannomin and neurofibromin we stained tumour paraffin sections of six patients with antibodies against peptides of the NF1 and the NF2 protein. Based on preserved immunoreactivities we were able to exclude diagnosis of NF1 in three and NF2 in two cases. In four patients the clinical symptoms could confirm the diagnosis of schwannomatosis. Combining the results of clinical, neurogenetical and immunohistochemical examinations we could diagnose NF1 or NF2 in ten patients in total. Immunoreactivity led to the suggestion of NF2 in two patients; the other two patients whose tumours were not stained so far, could as yet not be classified for NF.

Adult↗

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