Long-term follow-up of von Recklinghausen neurofibromatosis. Survival and malignant neoplasms

Classification and pathology

Soft tissue tumors are a heterogeneous group of benign and malignant processes. Some are assumed to be reactive; others are clearly neoplastic. Because of their rarity, they frequently pose diagnostic problems for surgical pathologists. Accurate diagnosis of these tumors is enhanced by knowledge of the clinical features of the given lesions and, at times, by application of immunohistochemical and molecular techniques. In this article the lesions are described essentially in accordance with the World Health Organization classification.

DNA copy number changes in high-grade malignant peripheral nerve sheath tumors by array CGH

Background

Malignant peripheral nerve sheath tumors (MPNSTs) are rare and highly aggressive soft tissue tumors showing complex chromosomal aberrations. In order to identify recurrent chromosomal regions of gain and loss, and thereby novel gene targets of potential importance for MPNST development and/or progression, we have analyzed DNA copy number changes in seven high-grade MPNSTs using microarray-based comparative genomic hybridization (array CGH).

Results

Considerable more gains than losses were observed, and the most frequent minimal recurrent regions of gain included 1q24.1-q24.2, 1q24.3-q25.1, 8p23.1-p12, 9q34.11-q34.13 and 17q23.2-q25.3, all gained in five of seven samples. The 17q23.2-q25.3 region was gained in all five patients with poor outcome and not in the two patients with disease-free survival. cDNA microarray analysis and quantitative real-time reverse transcription PCR were used to investigate expression of genes located within these regions. The gene lysyl oxidase-like 2 (LOXL2) was identified as a candidate target for the 8p23.1-p12 gain. Within 17q, the genes topoisomerase II-α (TOP2A), ets variant gene 4 (E1A enhancer binding protein, E1AF) (ETV4) and baculoviral IAP repeat-containing 5 (survivin) (BIRC5) showed increased expression in all samples compared to two benign tumors. Increased expression of these genes has previously been associated with poor survival in other malignancies, and for TOP2A, in MPNSTs as well. In addition, we have analyzed the expression of five micro RNAs located within the 17q23.2-q25.3 region, but none of them showed high expression levels compared to the benign tumors.

Conclusion

Our study shows the potential of using DNA copy number changes obtained by array CGH to predict the prognosis of MPNST patients. Although no clear correlations between the expression level and patient outcome were observed, the genes TOP2A, ETV4 and BIRC5 are interesting candidate targets for the 17q gain associated with poor survival.

Management of childhood malignant peripheral nerve sheath tumor

Malignant peripheral nerve sheath tumor (MPNST) is rare, but is one of the most frequent non-rhabdomyosarcoma soft-tissue sarcomas in the pediatric population. These tumors occur most frequently at axial sites and are characterized by local aggressiveness and a propensity to metastasize. They are often associated with neurofibromatosis type 1 (NF-1): the lifetime risk of patients with NF-1 developing MPNST has been estimated at 8-13%, compared with 0.001% in the general population. Because of the rarity of this tumor, little information is available on its clinical management, particularly in the pediatric age group. In a recent report on the clinical findings and treatment outcomes from a large number of children and adolescents with MPNST in an Italian and German series, less satisfactory overall outcomes than those for other pediatric sarcomas were described. Therefore, the approach to the treatment of patients with MPNST should be aggressive and risk adapted, and is necessarily complex. Patients should be referred to selected institutions with adequate experience in treating soft-tissue sarcomas, and with the multidisciplinary skills for enrolling patients in clinical trials. Surgical resection represents the mainstay of treatment, while the role of adjuvant treatment is not yet clear. Post-operative radiotherapy seems to have a role in improving local control, although the potential morbidity of irradiation should be taken into account, particularly when treating children. Although lack of local control is the major cause of treatment failure, MPNST may give rise to distant metastases. These tumors are usually considered as having uncertain chemosensitivity, but recent evidence suggests that there may be a role for chemotherapy in patients with a high-grade histology. For the near future, our hopes lie in the development of novel tailored therapies directed specifically against the molecular targets of the neoplastic cells: soft-tissue sarcomas seem particularly promising candidates for targeted therapy.

Diffuse ganglioneuromatosis in small intestine associated with neurofibromatosis type 1

Ganglioneuromatosis of the gastrointestinal tract is a rare condition that has an established association with the multiple endocrine neoplasia syndrome, type IIb. Its occurrence in neurofibromatosis, in which the large intestine is usually affected, is much rarer. We report a case of diffuse ganglioneuromatosis of the small bowel, found incidentally during surgery for a malignant peripheral nerve sheath tumor arising in the retroperitoneum in a 32-year-old man with neurofibromatosis type 1, and review previously reported cases.

Multiple pilocytic astrocytomas of the cerebellum in a 17-year-old patient with neurofibromatosis type I

OBJECTIVE

Approximately 10% of patients with neurofibromatosis I (NFI) patients will have central nervous system (CNS) tumors. The most common of these are hypothalamic-optic gliomas, followed by brainstem and cerebellar pilocytic astrocytomas. While isolated pilocytic astrocytomas in NFI are well described, the appearance of multiple pilocytic astrocytomas in an individual patient is less common. The most frequent combination in NFI patients with more than one pilocytic astrocytoma is optic tract/hypothalamic and brainstem. Other combinations are exceedingly rare; multiple pilocytic astrocytomas have only been reported once in the cerebral hemispheres in a patient with NFI. This report presents the first documented case, to our knowledge, of multiple pilocytic astrocytomas in the cerebellum of a patient with NF1.

METHODS

Case report.

CONCLUSION

The finding of multiple cerebellar pilocytic astrocytomas in a patient with NF1 is important because it expands the spectrum of presentations for patients with NF1 and also highlights specific diagnostic and therapeutic challenges faced by the treating physicians. The genetic and molecular basis of NF1 is reviewed. Strategies of diagnosis and treatment outlined here are relevant to both patients with NF1 and all patients with multiple posterior fossa tumors.

Fatal malignant melanoma in a child with neurofibromatosis type 1

Neurofibromatosis type 1 is an autosomal dominant disease and is considered one of the most commonly inherited diseases in humans. Malignant melanoma has been reported in up to 5% of patients with neurofibromatosis type 1. We report a young Saudi boy with neurofibromatosis type 1 who developed fatal metastatic malignant melanoma arising from giant melanocytic nevi within speckled lentiginous nevus (SLN).

Somatic alterations of the NF1 gene in an NF1 individual with multiple benign tumours (internal and external) and malignant tumour types

Neurofibromatosis type 1 is a common familial cancer syndrome, affecting about 1 in every 4,000 individuals worldwide. We have carried out NF1 gene mutation analysis on DNA isolated from 25 tumours (dermal and plexiform neurofibromas, malignant peripheral nerve sheath tumour, MPNST), obtained at post-mortem from an NF1 patient. Macro and micro sequence alterations of the NF1 gene were studied by dHPLC, microsatellite, RFLP markers and multiplex ligation probe amplification (MLPA). The underlying germline mutation involves a deletion of exons 2 and 3. Of the 25 tumours studied from this patient, characterised somatic mutations were identified in 9 tumours, these were six small deletions (748del T, 2534-2557 del 24bp, 2843delA, 3047-3048 del GT, 4743del G, 7720-7721 delAA), an insertion 649 ins 73 bp, a non-sense mutation R1513X and a single splice site mutation, IVS4C-1 G>A, eight of these represent novel sequence changes in the gene. Evidence for loss of heterozygosity (LOH) was identified in DNA from 7 of the tumours. Each of the tumours analysed contained a different somatic NF1 mutation, indicating that each tumour is the result of an independent somatic event. The somatic mutation detection rate in this study is 64% (16/25), is one of the highest rates in genomic DNA reported so far in a single NF1 patient. Only 68 characterised NF1 somatic mutations have so far been reported and so our data will contribute to NF1 somatic mutational spectrum of the NF1 gene and will be important for understanding the molecular basis of NF1 tumorigenesis.

Soft-tissue sarcomas in children and adolescents with neurofibromatosis type 1

BACKGROUND

Patients affected by neurofibromatosis type 1 (NF1) are at higher risk of developing soft-tissue sarcomas (STS) than the general population. The clinical findings and outcome in 43 children and adolescents with NF1 treated for STS in the Italian protocols between 1988 and 2004 are reported.

METHODS

The study included 37 patients with neurogenic sarcomas (36 malignant peripheral nerve sheath tumors [MPNST], 1 triton tumor) and 6 cases of rhabdomyosarcoma (RMS). The prevalence of NF1 observed during the study period was 43% in the MPNST population and 1% in the RMS group.

RESULTS

Most patients with neurogenic sarcomas had large, invasive tumors. Five-year event-free and overall survival rates were 19% and 28%, respectively. Two of 16 patients with evaluable disease responded to chemotherapy. All 6 RMS patients were </=3 years old and had embryonal subtype, 5 of 6 arising in the genitourinary tract or pelvis (paravesical); 4 were alive in first remission at the time of the analysis, 1 was alive in second remission after a local recurrence, and 1 died of disease.

CONCLUSIONS

The occurrence of STS in pediatric patients with NF1 syndrome in Italy is discussed, confirming that NF1 patients have a high risk of developing STS, and particularly MPNST, often with an aggressive clinical presentation and poor outcome. Cases of RMS tended to have particular features (early age, embryonal histotype, genitourinary site) and their outcome seemed to resemble that of the general RMS population.

Recent developments in neurofibromatosis type 1

PURPOSE OF REVIEW

This review summarizes the recent clinical and genetic developments in neurofibromatosis type 1 (NF1) and provides an insight into the possible underlying pathomechanisms.

RECENT FINDINGS

NF1, or von Recklinghausen disease, is one of the most common hereditary neurocutaneous disorders in humans. Clinically, NF1 is characterized by café-au-lait spots, freckling, skin neurofibroma, plexiform neurofibroma, bony defects, Lisch nodules and tumors of the central nervous system. The responsible gene, NF1, encodes a 2818 amino acid protein (neurofibromin). Pathological mutations range from single nucleotide substitutions to large-scale genomic deletions dispersed throughout the gene. In addition to the conventional mutation screening methods, a DNA chip microarray-based technology, combinational sequence-based hybridization, has been introduced to expedite mutation detection. Functional analysis has become more amenable following the development of the following: (1) primary Schwann cell cultures from NF1 patients; (2) mouse models; (3) proteomic technologies; and (4) mRNA silencing by RNA interference. These studies have shown that neurofibromin plays a role in adenylate cyclase and AKT-mTOR mediated pathways. It also appears to affect Ras-GTPase activating protein activity through the phosphorylation of protein kinase C which impacts on cell motility by binding with actin in the cytoskeleton.

SUMMARY

Recent advances in the clinical features and molecular genetics of NF1 will be discussed together with insights into the underlying pathomechanisms of NF1.

Women with neurofibromatosis 1 are at a moderately increased risk of developing breast cancer and should be considered for early screening

BACKGROUND

Malignancy risks in patients with neurofibromatosis 1 (NF1) are increased, but those occurring outside of the nervous system have not been clearly defined.

AIM

To evaluate the risk of breast cancer in women with NF1 in a population-based study.

METHODS

The risk of breast cancer in a cohort of 304 women with NF1 aged >or=20 years was assessed and compared with population risks over the period 1975-2005 using a person-years-at-risk analysis.

RESULTS

There were 14 cases of breast cancers in the follow-up period, yielding a standardised incidence ratio (SIR) of 3.5 (95% CI 1.9 to 5.9). However, six breast cancers occurred in women in their 40s, and the SIR of breast cancer in women aged <50 years was 4.9 (95% CI 2.4 to 8.8).

INTERPRETATION

Women with NF1 aged <50 years have a fivefold risk of breast cancer, are in the moderate risk category and should be considered for mammography from 40 years of age.

Further evidence of the increased risk for malignant peripheral nerve sheath tumour from a Scottish cohort of patients with neurofibromatosis type 1

A recent study, looking at the lifetime risk of developing malignant peripheral nerve sheath tumour (MPNST) in patients with neurofibromatosis type 1 (NF1), estimated the risk to be 8-13%. Prior to this, longitudinal studies had shown that patients with NF1 had a risk of 4-5% of developing MPNST, and cross-sectional studies had found that only 1-2% of patients with NF1 had MPNST. The aim of this study was to estimate the lifetime risk of MPNST in patients with NF1 in southern Scotland, using patient records obtained from the Edinburgh and Glasgow Genetic Units and Scottish Cancer Register. In the period 1993-2002, 14 patients with NF1 were diagnosed with MPNST in a population of 3.5 million. The lifetime risk of MPNST in the Scottish patients with NF1 was calculated to be 5.9-10.3%. This provides further evidence that patients with NF1 are at greater risk of developing MPNST than was previously estimated, and emphasises the importance of educating patients about suspicious symptoms, which may need an urgent medical opinion. The mean age at diagnosis of MPNST (p<0.05) and 5-year survival (p<0.01) were significantly lower in patients with NF1 than in unaffected individuals. This may be due to patients with NF1 presenting later, because the tumour is mistaken for a neurofibroma, or due to MPNST having a more aggressive course in NF1.

Malignant peripheral nerve sheath tumour of the cervical vagus nerve in a neurofibromatosis type 1 patient

One serious complication of neurofibromatosis type 1 (NF1) is the development of malignant peripheral nerve sheath tumours (MPNSTs). These malignancies often develop within pre-existing plexiform neurofibromas and their development is now thought to be associated with both tumour suppressor gene mutations and dysregulated growth factor signalling. Recent work demonstrates that the lifetime risk of malignant transformation is significantly greater than previously thought. Ionising radiation, a long-standing disease, particularly the presence of a large number of plexiform neurofibromas from an early age, are suggested risk factors. We present an NF1 patient who developed an MPNST of the cervical vagus nerve which was successfully treated with surgery. Close monitoring of patients with NF and a high level of suspicion towards rapidly enlarging and painful swellings is merited as these features may signify malignant transformation. Whether a positive history of MPNST in other affected family members predisposes the individual to a higher risk of malignant transformation is unclear.

EGF genetic polymorphism is associated with clinical features but not malignant phenotype in neurofibromatosis type 1 patients

Neurofibromatosis type 1 (NF1) is characterized by a wide variation in clinical presentation and in some cases progression to malignant tumor. Epidermal growth factor (EGF) is an important mitogen for Schwann cells and is involved in the development of malignant tumors in NF1 patients. We hypothesized that EGF +61 G/A functional polymorphism, which represents constitutional all-life exposure to higher EGF expression and circulating levels, may predispose for precocious and more aggressive manifestations of disease. We found that clinical findings of intestinal polyps are significantly more frequent in patients with G homozygous genotype (P = 0.023). Those carriers of GG genotype have earlier onset of café-au-lait spots and Lisch nodules appearance (P = 0.030 and P = 0.017, respectively). Nevertheless, the EGF overexpressing genotype-GG, is not associated with higher risk for malignant progression or severity of disease. EGF polymorphism may play a role in the earlier onset of NF1 pigment cell-related manifestations and in intestinal polyps' development. Further studies in larger samples should confirm the absence of risk for having higher severity grade or malignant phenotype in NF1 patients.

Syndromes and constitutional chromosomal abnormalities associated with Wilms tumour

Wilms tumour has been reported in association with over 50 different clinical conditions and several abnormal constitutional karyotypes. Conclusive evidence of an increased risk of Wilms tumour exists for only a minority of these conditions, including WT1 associated syndromes, familial Wilms tumour, and certain overgrowth conditions such as Beckwith-Wiedemann syndrome. In many reported conditions the rare co-occurrence of Wilms tumour is probably due to chance. However, for several conditions the available evidence cannot either confirm or exclude an increased risk, usually because of the rarity of the syndrome. In addition, emerging evidence suggests that an increased risk of Wilms tumour occurs only in a subset of individuals for some syndromes. The complex clinical and molecular heterogeneity of disorders associated with Wilms tumour, together with the apparent absence of functional links between most of the known predisposition genes, suggests that abrogation of a variety of pathways can promote Wilms tumorigenesis.

CyberKnife radiosurgery for benign intradural extramedullary spinal tumors

OBJECTIVE

Microsurgical resection of benign intradural extramedullary spinal tumors is generally safe and successful, but patients with neurofibromatosis, recurrent tumors, multiple lesions, or medical problems that place them at higher surgical risk may benefit from alternatives to surgery. In this prospective study, we analyzed our preliminary experience with image-guided radiosurgical ablation of selected benign spinal neoplasms.

METHODS

Since 1999, CyberKnife (Accuray, Inc., Sunnyvale, CA) radiosurgery was used to manage 51 patients (median age, 46 yr; range, 12-86 yr) with 55 benign spinal tumors (30 schwannomas, nine neurofibromas, 16 meningiomas) at Stanford University Medical Center. Total treatment doses ranged from 1600 to 3000 cGy delivered in consecutive daily sessions (1-5) to tumor volumes that varied from 0.136 to 24.6 cm.

RESULTS

Less than 1 year postradiosurgery, three of the 51 patients in this series (one meningioma, one schwannoma, and one neurofibroma) required surgical resection of their tumor because of persistent or worsening symptoms; only one of these lesions was larger radiographically. However, 28 of the 51 patients now have greater than 24 months clinical and radiographic follow-up. After a mean follow-up of 36 months, all of these later lesions were either stable (61%) or smaller (39%). Two patients died from unrelated causes. Radiation-induced myelopathy appeared 8 months postradiosurgery in one patient.

CONCLUSION

Although more patients studied over an even longer follow-up period are needed to determine the long-term efficacy of spinal radiosurgery for benign extra-axial neoplasms, short-term clinical benefits were observed in this prospective analysis. The present study demonstrates that CyberKnife radiosurgical ablation of such tumors is technically feasible and associated with low morbidity.

Tumors of the peripheral nerves and plexuses

Peripheral nerve tumors are a diverse group of lesions histologically and in their clinical behavior. The genetic disorders neurofibromatosis type 1 and 2 and schwannomatosis are significant risk factors for the development of peripheral nerve tumors. An understanding of these disorders is important in allowing appropriate management. Active treatment of peripheral nerve tumors is reserved for lesions that are malignant or causing neurologic dysfunction, pain, compressive symptomatology, or cosmetic concern. The mainstay of treatment is surgical intervention, the nature of which will vary with the type of tumor and anatomical location. In the case of malignant tumors, adjuvant chemotherapy and radiotherapy are commonly used. Developments in the understanding of the genetics and molecular biology of peripheral nerve tumors are opening up potentially exciting new avenues of treatment. The prognosis of benign peripheral nerve tumors is excellent, with a recurrence rate of just 5% or less after successful surgery. Malignant tumors have proven to be more challenging, with a much higher recurrence rate and a 5-year survival rate of 64%.

A prospective study of neurofibromatosis type 1 cancer incidence in the UK

Neurofibromatosis type 1 (NF1) is an autosomal dominant condition affecting around one in 3000 live births. The manifestations of this condition are extremely variable, even within families, and genetic counselling is consequently difficult with regard to prognosis. Individuals with NF1 are acknowledged to be at increased risk of malignancy. Several studies have previously attempted to quantify this risk, but have involved relatively small study populations. We present prospective data from 448 individuals with NF1 with a total of 5705 years of patient follow-up. These data have been collected via the UK NF1 association for patients. Demographic information on the affected individuals was cross-referenced with UK cancer registry data by the UK Office of National Statistics. The overall risk of cancer was 2.7 times higher in this cohort of NF1 patients than in the general population (95% confidence interval (CI) 1.9–3.7). The cumulative risk of a malignancy by age 50 years was 20% (95% CI 14–29%); beyond this age, the risk of cancer was not significantly elevated (P=0.27). The most frequent types of cancer were connective tissue (14% risk by age 70, 95% CI 7.8–24%) and brain tumours (7.9, 95% CI 3.9–16%). There was no statistically significant excess of cancers at other sites (P=0.22).

Malignant peripheral nerve sheath tumors with high and low Ras-GTP are permissive for oncolytic herpes simplex virus mutants

BACKGROUND

Malignant peripheral nerve sheath tumors (MPNSTs) occur most frequently in patients with neurofibromatosis type 1 and are often fatal. Current therapy relies upon radical surgical resection, which often fails to completely remove the tumor. To address the need for novel treatment approaches for this disease, we sought to determine if human MPNST-derived cell lines are sensitive to oncolytic Herpes simplex virus (oHSV) infection. Activation of the Ras pathway and its inhibitory effects on protein kinase R (PKR) activation have been shown to dictate cellular permissivity to oHSV mutants. Because NF-1-associated MPNSTs possess inherent hyperactive Ras, we hypothesized these tumors would be ideal therapeutic targets for oHSVs.

PROCEDURE

Human MPNST-derived cell lines were examined for sensitivity to oHSV-mediated gene transduction, virus replication, cytotoxicity, and apoptosis. These parameters were correlated with PKR activation following oHSV infection and compared with normal human Schwann cells (NHSCs) without hyperactive Ras.

RESULTS

MPNST-derived cell lines were efficiently transduced, supported virus replication and were killed by the oncolytic HSV mutants, including sporadic MPNSTs without hyperactive Ras. In contrast to the highly sensitive MPNST cell lines, NHSCs did not support mutant virus replication.

CONCLUSIONS

MPNSTs are susceptible to lysis by oncolytic HSV mutants, regardless of Ras status. Tumor-selective virus replication in MPNST cells appears to be mediated by both cellular expression of ribonucleotide reductase and prevention of eIF2alpha phosphorylation. Virus-induced cytotoxicity of MPNST cell lines was caused by both direct lysis and apoptosis. Our data suggest the use of oncolytic HSV mutants may represent a novel treatment approach for patients with MPNSTs.

Diffuse large B-cell lymphoma arising in a patient with neurofibromatosis type I and in a patient with neurofibromatosis type II

We experienced two unusual cases of diffuse large B-cell lymphoma (DLBCL), which occurred in a patient with neurofibromatosis type I and a patient with neurofibromatosis type II. B-cell lymphoma is one of the most common phenotypic subgroups of malignant lymphoma. Neurofibromatosis I is characterized by café-au-lait spots and neurofibromas. Neurofibromatosis II typically consists of bilateral schwannomas of the acoustic nerve. Malignant lymphomas rarely coexist with neurofibromatosis I, and no coexistence with neurofibromatosis II has been reported. The patient with neurofibromatosis I was a 50-year-old Japanese woman, clinically manifesting von Recklinghausen's disease since infancy, who noticed an egg-sized tumor in her shoulder. The patient with neurofibromatosis II was a 39-year-old Japanese man who noticed multiple soft tissue tumors in his neck, buttock, and elbow. Biopsied materials from both cases were examined by multiparameter methods, including flow cytometry. Flow cytometry revealed large-scale cells to be tumor cells, and they were positive for CD19, CD20, and CD22. Both patients received chemotherapy, and the tumors disappeared. The patient with neurofibromatosis I was alive without recurrence at 4 years after treatment, while the patient with neurofibromatosis II died of recurrence. To the best of our knowledge, this is the first case of malignant lymphoma arising in a neurofibromatosis II patient. As for neurofibromatosis I, there were some reports about occurrence of malignant lymphoma. It is important to be aware of possibility of association of malignant tumors not only of the nervous system but also of unrelated to the nervous system when tumors appear in neurofibromatosis patients.

Osteosarcoma in a patient with neurofibromatosis type 1: a case report and review of the literature

Neurofibromatosis type 1 (NF1) or von Recklinghausen's disease is a genetic disease generally characterized by café-au-lait spots and neurofibromas. Malignant tumors of the nervous system, such as malignant schwannomas, gliomas, or astrocytomas, have been well known to coexist with neurofibromatosis. However, occurrence of malignant tumors unrelated to the nervous system is rare. We report an unusual case of a 29-year-old NF1 female suffering from malignant peripheral nerve sheath tumor (MPNST) that eventually developed osteosarcoma in the proximal femur. Osteosarcoma is the most common high-grade malignant bone tumor in which the neoplastic cells produce osteoid. At 23 and 24 years old, she underwent excision of MPNST in the left posterior thigh. No osteosarcomatous portion was identified in these specimens. The patient underwent postoperative chemotherapy. At 29, left proximal thigh pain and swelling appeared. Computed tomography demonstrated cortical bone destruction in the left proximal femur where MPNST occurred. Magnetic resonance imaging revealed extraskeletal growth of the tumor. Bone scintigraphy demonstrated increased uptake in the left proximal femur. Hip disarticulation was performed. The removed tumor was composed of highly anaplastic cells. Lace-like irregular osteoid formation was observed among the tumor cells. MPNST component was totally absent. The tumor was diagnosed as osteoblastic type osteosarcoma. Two months after disarticulation the patient died of bilateral pulmonary metastasis. The correlation between the histogenesis of osteosarcoma and the genetic abnormality in NF1 patients has not been elucidated, but the finding of osteosarcomatous transformation in this case suggests the divergent cellular differentiation to mesenchymal malignant tumors of neuroectodermal tissue in NF1 patients.

A case of intra-dural malignant peripheral nerve sheath tumor in thoracic spine associated with neurofibromatosis type 1

We present a 25-year-old male patient with neurofibromatosis type 1 (NF1). Thoracic intra-dural extra-medullary tumoral mass was excised gross-totally and the patient was referred to oncology unit. Histopathological diagnosis was malignant peripheral nerve sheath tumor (MPNST), a rare sarcoma with a dismal prognosis. Tumor recurred in its previous site with an adjacent apical mass in the left lung 7 weeks following initial surgery and repeat surgery was performed with complete removal of intra-dural tumor. We report the first patient with intra-dural MPNST localized proximal to conus medullaris; in upper thoracic spine. It must always be considered the possibility of a rare but a devastating tumor, MPNST beside schwannomas and neurofibromas in patients with NF1 when an intra-spinal mass is diagnosed.

Clinical manifestations and management of neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder with variable expression. The complications are age specific. Neurologic complications include tumors of the peripheral nerves, nerve roots, and plexi; spinal cord compression; dural ectasias; learning disabilities; attention deficit; headaches; seizures; brain tumors; deafness; hydrocephalus; and stroke. High-intensity signals on brain magnetic resonance imaging are a frequent finding without known clinical significance. Most brain tumors are benign and asymptomatic, but malignant brain tumors occur. The major cause of death is malignancy, including brain tumors and malignant peripheral nerve sheath tumors. Management includes genetic counseling, regular eye examinations, and careful physical exams.

Pediatric adrenal cortical carcinoma: brain metastases and relationship to NF-1, case reports and review of the literature

Adrenal cortical carcinoma (ACC) is a rare childhood neoplasm that seldom manifests brain metastases; hence few papers in the literature focus on neurological manifestations associated with ACC. Although ACC is known to be a signature tumor type in several inherited cancer predisposition syndromes, particularly Li Fraumeni, ACC has not been previously associated with neurofibromatosis, type 1 (NF-1), an inherited disorder with frequent CNS lesions that might prompt concern for metastatic disease by neuroimaging studies. We present two pediatric patients with ACC and unusual CNS findings. The first child developed metastasis to the brain 4 years after resection of his adrenal primary and 2 and 1 years, respectively, after metastases to the liver and lungs. Soon after our experience with this patient, a girl with known NF-1 presented with virilization; adrenalectomy disclosed an ACC and systemic metastases were found within months. Disseminated disease prompted concern that her complex intracranial lesions identified by neuroimaging studies might represent brain metastases, but this proved to be NF1-related hamartomatous lesions. We review the literature on ACCs in pediatric patients regarding brain metastases and previous associations with NF-1.

[Type I neurofibromatosis, pheochromocytoma and somatostatinoma of the ampulla. Literature review]

Gastrointestinal involvement in Von Recklinghausen's neurofibromatosis (autosomal dominant disease) is observed in 25% of patients and is frequently represented by duodenal carcinoids. We report a case of somatostatinoma of the ampulla in a 42-year-old female with neurofibromatosis and pheochromocytoma and show a literature review about the association of neurofibromatosis and somatostatinoma. This pathological association appears non hasardous and surgical ampullectomy offers a good alternative to pancreaticoduodenectomy in localised tumors treatment.

Neurofibromatosis-associated nerve sheath tumors

In this paper the authors describe a patient with neurofibromatosis Type 1 (NF1) who presented with sequelae of this disease. They also review the current literature on NF1 and NF2 published between 2001 and 2005.

The method used to obtain information for the case report consisted of a family member interview and a review of the patient's chart. For the literature review the authors used the search engine Ovid Medline to identify papers published on the topic between 2001 and 2005. Neurofibromatosis Type 1 appears in approximately one in 2500 to 4000 births, is caused by a defect on 17q11.2, and results in neurofibromin inactivation. The authors reviewed the current literature with regard to the following aspects of this disease: 1) diagnostic criteria for NF1; 2) criteria for other NF1-associated manifestations; 3) malignant peripheral nerve sheath tumors (PNSTs); 4) the examination protocol for a patient with an NF1-related NST; 5) imaging findings in patients with NF1; 6) other diagnostic studies; 7) surgical and adjuvant treatment for NSTs and malignant PNSTs; and 8) hormone receptors in NF1-related tumors. Pertinent illustrations are included.

Neurofibromatosis Type 2 occurs much less frequently than NF1, that is, in one in 33,000 births. Mutations in NF2 occur on 22q12 and result in inactivation of the tumor suppressor merlin. The following data on this disease are presented: 1) diagnostic criteria for NF2; 2) criteria for other NF2 manifestations; 3) malignant PNSTs in patients with NF2; 4) examination protocol for the patient with NF2 who has an NST; and 5) imaging findings in patients with NF2. Relevant illustrations are included.

It is important that neurosurgeons be aware of the sequelae of NF1 and NF2, because they may be called on to treat these conditions.

Classification of pleomorphic sarcomas: where are we now?

Until a decade ago, so-called pleomorphic and storiform malignant fibrous histiocytoma (MFH) represented the most frequently diagnosed sarcoma, accounting for approximately 40% of adult mesenchymal malignancies. However, the latest World Health Organization classification of soft tissue tumours considers MFH a synonym for undifferentiated pleomorphic sarcoma. Historically, the term MFH was introduced in the medical literature in 1963 by Ozzello, O'Brien and Stout, on the basis of the acquisition of phagocytic properties observed in cultured fibroblasts. The existence of MFH as a well-defined clinicopathological entity became rapidly very popular and by the mid 1980s MFH represented the most common sarcoma in adults. With the advent of electron microscopy, immunohistochemistry and molecular genetics, it became clear that the so-called "facultative fibroblast" theory had no scientific grounds and, in 1992, a milestone paper eventually brought attention to the concept that MFH merely represented a morphological pattern shared by a wide variety of poorly differentiated malignant neoplasms, which include specific subtypes of pleomorphic sarcomas. Currently, accurate subclassification of pleomorphic sarcomas is mandatory as it enables recognition of non-sarcomatous lesions as well as pleomorphic neoplasms not associated with aggressive behaviour. Furthermore, as myogenic differentiation predicts aggressive clinical behaviour among pleomorphic sarcomas, precise histotyping allows prognostic stratification of patients.

Malignant peripheral nerve sheath tumors

BACKGROUND

The authors explored the prognostic factors and clinical outcomes of patients who had malignant peripheral nerve sheath tumors (MPNST) with and without neurofibromatosis type 1 (NF-1).

METHODS

Two hundred five patients with localized MPNST who underwent surgery at the Istituto Nazionale per lo Studio e la Cura dei Tumori (Milan, Italy) over 25 years were reviewed. Forty-six patients had concomitant NF-1 syndrome, and 159 patients did not. Local recurrence, distant metastases, and survival rates were studied.

RESULTS

One hundred thirty patients presented with primary disease, and 75 patients had locally recurrent tumors. The disease-specific mortality rate was 43% at 10 years, with a continuously disease-free survival rate of no greater than 40%. Presentation with either primary or recurrent disease, tumor size, and tumor site (trunk vs. extremity) were the strongest independent predictors of survival. Margin status and radiation therapy also played a role, mostly related to their effect on local outcome. Pathologic grade influenced distant metastases, but only a trend for survival could be observed. No significant independent differences between patients with and without NF-1 were observed.

CONCLUSIONS

To the authors' knowledge, this was among the largest single-institution series to date. The results confirmed that patients with MPNST share similar prognostic factors with patients who have other soft tissue sarcomas and have some of the worst clinical outcomes. The presence of NF-1 syndrome per se did not affect survival, but patients with NF-1 were more likely to have larger tumors. Therefore, such patients should be followed carefully to detect disease as early as possible.

[Orbito-temporal plexiform neurofibroma: 6 cases]

INTRODUCTION

Orbito-temporal plexiform neurofibroma is characteristic of Von Recklinghausen neurofibromatosis. We report 6 cases of orbito-temporal plexiform neurofibromas and review different aspects of diagnosis, course and treatment.

PATIENTS AND METHODS

Six patients, 4 males and 2 females, with orbito-temporal plexiform neurofibromas were treated between 1986 and 2003. Patient age varied between 10 and 29 years (age average=19). Computed tomography and magnetic resonance imaging were performed in all 6 patients. Surgical resection of the neurofibroma was performed in all patients.

RESULTS

The tumor was located on the left in 5 cases and on the right in one. Spheno-orbital dysplasia was found in all patients and was associated with fronto-temporal meningoencephalocele and pulsate exophthalmia. Surgical resection enabled reduction of the neurofibroma. Exenteration was performed in all patients because of a nonfunctional eye. Two patients underwent cure of fronto-temporal meningoencephalocelus with reconstruction of the large wing of the sphenoid using an iliac bone graft and a titanium plate.

DISCUSSION

Surgery is essential for orbito-temporal plexiform neurofibroma but is usually difficult, particularly when the tumor has developed increasing the risk of hemorrhage. Bony reconstruction is difficult considering the risk of progressive osseous dysplasia. The cosmetic results achieved in this patient were considered good.

Expression and Function of Somatostatin Receptors in Peripheral Nerve Sheath Tumors

Although somatostatin receptors have been detected in many normal and neoplastic tissues, little is known of their expression and function in peripheral nerve tumors. In the present study, we examined the expression of all 5 somatostatin receptor subtypes (sst1-5) in 3 normal peripheral nerves, 3 traumatic neuromas, 27 schwannomas, 18 neurofibromas, and 177 malignant peripheral nerve sheath tumors (MPNSTs) by immunohistochemistry as well as by Western blot and reverse transcriptase-polymerase chain reaction investigations in 2 normal peripheral nerves, one neurofibroma, 5 schwannomas, and 5 MPNSTs. Immunoreactive somatostatin receptors were not detectable in normal peripheral nerve and in nonneoplastic Schwann cell proliferations. In contrast, sst2A mRNA and protein was present in 89% of schwannomas. This receptor subtype was less frequently detected in neurofibromas (22%) and MPNSTs (15%). Interestingly, sst4 was seen in 32% of MPNSTs and was almost exclusively expressed in this malignant tumor type. In support of a role in Schwann cell tumor growth control by somatostatin was the observation of induced internalization of sst2A and inhibition of cell proliferation in an NF1-associated MPNST cell line. Moreover, administration of an sst2A-selective agonist resulted in induction of MPNST cell apoptosis. We conclude that peripheral nerve sheath tumors often express at least one functional somatostatin receptor. Furthermore, our findings suggest a potential clinical role for somatostatin receptor agonists in tumor imaging and/or treatment of schwannomas and MPNSTs.

Divergent differentiation in malignant soft tissue neoplasms: the paradigm of liposarcoma and malignant peripheral nerve sheath tumor

In tumors clonality does not always translate into morphologic uniformity. While most sarcomas exhibit only one line of histologic differentiation, a minority may display a strikingly diverse phenotype in addition to the main lineage. This phenomenon not only presents a diagnostic problem but also raises questions about the commitment of tumor cells toward a specific phenotype. Among sarcomas, malignant peripheral nerve sheath tumor (MPNST) and dedifferentiated liposarcoma are two entities in which divergent differentiation is a relatively frequent event. Diagnostically it is crucial to recognize the "primary" sarcoma in such tumors correctly and distinguish it from the "secondary" divergent elements. The presence of the latter could be the first morphologic clue to a specific sarcoma type. Even though it may be difficult to explain the pathogenesis of divergent differentiation, divergence still illustrates that the phenotype of a tumor cell is not set in stone but can be modulated or switched by a number of factors.

Adenoid glioblastoma arising in a patient with neurofibromatosis type-1

An unusual case of glioblastoma with adenoid structures arising in a 30-year-old Japanese woman with neurofibromatosis type-1 (NF1) is reported. The patient was admitted to University of Miyazaki Hospital, complaining of headache, nausea and vomiting. From the neuroradiological findings the patient was diagnosed as having glioblastoma, and the tumor was surgically resected. Histologically, the tumor consisted mainly of dark basophilic cells showing prominent tubular or glandular structures surrounded by large eosinophilic cells, in addition to the typical glioblastoma features in the periphery of the tumor. Both cells showed strong stainability with glial fibrillary acidic protein (GFAP) and S-100 protein immunohistochemically, so that the tumor was classified as adenoid glioblastoma. Several cases of glioblastoma have been reported to reveal the adenoid or epithelioid differentiation. The patients with NF1 are prone to develop malignant tumors including glioblastoma, but no cases representing adenoid glioblastoma associated with NF1 have been reported. This report is considered to be the first case of adenoid glioblastoma arising in a patient with NF1. The recognition of the existence of epithelial features of glioblastoma would be important in differential diagnosis of epithelioid tumors of the brain including metastatic carcinomas.

Subcutaneous neurofibromas are associated with mortality in neurofibromatosis 1: a cohort study of 703 patients

Neurofibromatosis 1 (NF1) is a common genetic disorder with an autosomal dominant mode of inheritance, an increased morbidity and mortality, and a shorter lifespan. Although the disease is fully penetrant by the age of 8, the variability in symptoms and complications is high, even among members of the same family. The aim of this study was to identify easily recognizable clinical features that may be associated with mortality in a cohort of patients affected with NF1. We used prospectively collected data from the Neurofibromatosis Institute Database (NFID) and included in our analysis 703 patients who fulfilled the NIH diagnostic criteria for NF1. Clinical, especially dermatological features were tested as potential factors associated with mortality. Among the patients, 405 (57.6%) were children and 298 (42.4%) were adults. The mean follow-up was 2.4 years (median = 0.98, range: 0-15.3 years). Forty patients died during follow-up, mostly due to tumor development such as sarcoma (n = 18). In the adult population, subcutaneous neurofibromas (odds ratio [OR] = 3.6, 95% confidence interval (CI): [1.2-11.3], P = 0.02) and male gender (OR = 5.6, [1.5-20.9], P = 0.004) were independent predictors of mortality after adjustment for age. Among children, the presence of facial plexiform neurofibromas and pruritus were significantly associated with mortality in univariate analysis. Our study describes independent risk factors of mortality in a large cohort of adult and pediatric patients. Close follow-up should be obtained for patients presenting with subcutaneous neurofibromas.

Malignant peripheral nerve sheath tumor in neurofibromatosis type I: unusual presentation of intraabdominal or intrathoracic mass

A malignant peripheral nerve sheath tumor (MPNST) is an extremely rare soft tissue tumor in the general population. On the other hand, there is a higher incidence of MPNST in patients with neurofibromatosis type I (von Recklinghausen's disease). The common sites are the extremities, trunk, head and neck. However, an intraabdominal or intrathoracic manifestation is uncommon. This paper reports two patients, a 31 year-old woman with multiple neurofibromatosis presenting as an intraabdominal malignant peripheral nerve sheath tumor, and a 33 year-old woman with an intrathoracic malignant peripheral nerve sheath tumor. The patients were treated with chemotherapy followed by radiotherapy. However, one patient died as a result of disease progression 21 months after the diagnosis and the other patient is currently being treated with radiotherapy.

La neurofibromatose 1 (NF1) ou maladie de Von Recklinghausen

OBJECTIVES

Neurofibromatosis 1(NF1) is one of the most common genetic diseases. NF1 is an autosomal dominant genetic disorder and half of affected individuals have NF1 as the result of a new gene NF1 mutation. The offspring of an affected individual have a 50% risk of inheriting the altered NF1 gene. The disease manifestations are extremely variable, even within a family. NF1 is characterized by multiple cafe au lait spots, axillary and inguinal freckling, multiple discrete dermal neurofibromas, and iris Lisch nodules. Learning disabilities are frequent. Less common but potentially more serious manifestations include plexiform neurofibromas, optic and other central nervous system gliomas, malignant peripheral nerve sheath tumors, vasculopathy, and osseous lesions.

CURRENT KNOWLEDGES AND KEY POINTS

Since the original National Institutes of Health consensus Development Conference in 1987, there have been significant progress toward a more complete understanding of the molecular-bases for neurofibromatosis 1 and the routine follow-up for the care of the NF1 patients. The authors review the present data on the clinical and molecular aspects of the neurofibromatosis 1.

FUTURE PROSPECTS AND PROJECTS

NF1 requires life-long management adapted to age and multidisciplinary structures are particularly well adapted to the diversity of the manifestations of this pathology. The French NF-France Network has been created in 2001 to federate the French multidisciplinary structures for neurofibromatosis and harmonize the follow-up of NF1 patients in France.

MR imaging of abdominopelvic involvement in neurofibromatosis type 1: a review of 43 patients

BACKGROUND

Plexiform neurofibromas are a frequent complication of neurofibromatosis type 1. This article discusses MR imaging findings and distribution of plexiform neurofibromas in the abdomen and pelvis.

OBJECTIVE

To define the most prevalent patterns of involvement and MR imaging findings in abdominopelvic neurofibromatosis type 1.

MATERIALS AND METHODS

We reviewed the MR appearance of abdominopelvic lesions in 23 male and 20 female patients (median age: 16 years) with type 1 neurofibromatosis. The patients were part of a multi-institutional study of 300 patients. Imaging included coronal or sagittal, and axial short tau inversion recovery images.

RESULTS

The most common abdominopelvic involvement was in the abdominopelvic wall (n=28, 65%) and lumbosacral plexus (n=27, 63%). Retroperitoneal involvement was frequent (n=15, 35%). Lesions were less often intraperitoneal (21%) (P=0.001). Pelvic disease (n=27, 63%), neural canal involvement (n=18, 42%), and hydronephrosis (n=4, 9%) were also noted. Target-like appearance of plexiform lesions was noted in more than half the patients.

CONCLUSION

Abdominopelvic involvement in neurofibromatosis type 1 is primarily extraperitoneal. Although lesions are most prevalent in the abdominopelvic wall and lumbosacral plexus, retroperitoneal and pelvic involvement is common and usually affects important organs. MR imaging added information in the initial and follow-up clinical evaluation of these patients.

Epithelioid hemangioendothelioma and multiple thoraco-lumbar lateral meningoceles: two rare pathological entities in a patient with NF-1

Epithelioid hemangioendothelioma (EHE) is a rare vascular soft-tissue tumour of intermediate malignancy. Neurofibromatosis type I (NF-1) is a genetic syndrome associated with soft tissue sarcoma and higher risk of developing neoplasia. Lateral meningoceles are uncommon entities, being mostly associated with NF-1. We report a case of a 31-year-old woman, with NF-1 and past history of right thalamic/peduncular astrocytoma WHO grade II, admitted to the Neurosurgery Department in December 2003 due to severe low back pain, irradiating to the left leg without a radicular pattern. Thoraco-lumbar magnetic resonance imaging (MRI) showed a large left posterior paravertebral expansive lesion, bilateral and multiple thoraco-lumbar lateral meningoceles and dural ectasias with scalloping of the vertebral bodies. Biopsy of the paravertebral mass lesion disclosed EHE. We present this case because of the novel association between NF-1 and EHE, and the unusual aggressiveness of the neoplasia. Additionally, we highlight the co-existence of bilateral and multiple lateral meningoceles.

Cutaneous malignant melanoma and neurofibromatosis type 1

Neurofibromatosis 1 (NF1) is a genetically transmitted disease occurring approximately once in 3000 live births and resulting from mutations of the NF1 gene that encodes a protein named neurofibromin, a negative regulator of the ras-dependent pathway. An excess of neoplasia especially tumours of neuroectodermal origin is classically observed. The occurrence of malignant melanoma in patients with NF1 has already been described in scattered clinical reports but little is known as to the characteristics of melanoma arising in NF1 patients. A multicentric retrospective study was conducted on a panel of French referring centres for a period of 13 years to identify patients with both melanoma and NF1. Patients with mucosal or ocular melanoma were excluded. The diagnosis of malignant melanoma was based on specific histology whereas NF1 was identified according to the criteria proposed by the NIH Consensus Conference. All patient fulfilling criteria for both melanoma and NF1 were investigated using a common procedure recording clinical and histological data along with prognostic factors for the two diseases. Eleven patients were identified with both diseases. The clinical pattern of NF1 was quite similar to the classical form of the disease, but some unusual features were present as regards to the melanoma: a sex-ratio of 10 women for one man and an average age lower than expected (median age=33 years) for melanoma occurrence. Among prognostic factors, median thickness was high compared to large series of melanoma in the literature (3.20 versus 1.5 mm). Another neoplasia occurred in three patients. An increase in melanoma incidence in patients with NF1 remains hypothetical but our small series of malignant melanoma arising in NF1 patients displays a large female preponderance, a higher thickness than expected and a frequent association with a second neoplasia. The peculiar female proneness for cancer whatever its localization and the risk of multiple neoplasias have already been reported in NF1 patients and could be true for malignant melanoma as well.

Peripheral nerve tumors: management strategies and molecular insights

Because of its relative rarity and a wide variety of clinical manifestations, peripheral nerve tumors (PNTs) often present to specialists from widely different disciplines, thus often resulting in delayed diagnosis and a non-cohesive pattern of management. Critical appraisal of the history and physical examination followed by radiological investigations, by experienced medical personnel, ultimately suggests that the extremity mass is perhaps a PNT, rather than the wide variety and more common soft tissue tumors. Included in this appraisal is a search for a pre-disposition syndrome, the most common of which are neurofibromatosis-1 and -2 (NF1, NF2) and schwannomatosis, which may require life-long careful follow up. Intra-operative and post-operative management decisions in a multidisciplinary manner with knowledge of the biological, pathological and clinical behavior of the PNT, is of utmost importance. In the context of pre-disposition syndromes, where multiple tumors may exist along with other nervous system lesions, molecular biological insights and hopefully the biological therapies that stem from this knowledge are of interest. In this article the spectrum of PNTs and their management protocols, including the algorithm for treatment of malignant PNTs advocated by our institute, are presented and currently available genetic insights and probable role of experimental therapies are briefly reviewed.

Scalp malignant peripheral nerve sheath tumor (MPNST) with bony involvement and new bone formation: case report

Malignant peripheral nerve sheath tumors (MPNSTs) are rare neoplasms, usually arising from somatic soft tissues or peripheral nerves. Primary MPNST of the scalp is extremely rare, with only a single case reported so far. Here, we describe an unusual case of scalp MPNST in a 50-year-old male. The tumor was associated with bony projection, intracranial extension and underlying bone destruction. The tumor was treated with complete surgical excision followed by adjuvant radiotherapy. Histologically, the tumor showed malignant spindle cells with focal S-100 positivity on immunohistochemistry and a diagnosis of MPNST was made. This case is being reported for its rarity and presence of associated bony projection, which to the best of our knowledge, has not been described before in soft tissue sarcomas.

Malignant peripheral nerve sheath tumors

The rarity of MPNSTs and the lack of any singular diagnostic radiologic or pathologic signature lead to several management challenges. These tumors are best managed as part ofa multidisciplinary team so as to optimize patient care and facilitate research. Suspicion of an MPNST based on clinical or radiologic alteration of a soft tissue mass in proximity to a peripheral nerve, especially in the context of NF I, should lead to referral to such a tertiary center. Early diagnosis followed by oncologic surgery to obtain tumor-free margins provides the best chance for long-term cure. Psychologic support and occupational rehabilitation are vital components of the overall care of these relatively young patients faced with often disabling surgery. Current adjuvant therapy with radiation and chemotherapy is suboptimal. There have been major inroads toward the molecular biologic understanding of MPNSTs,with several biologic targets that are of potential therapeutic interest. Proper evaluation of these novel and promising management strategies requires a concerted effort to refer these patients to the tertiary centers through which multi-institutional clinical trials can be undertaken.

Molecular pathogenesis of astrocytic tumours

Our current knowledge of the molecular pathogenesis of the diffuse adult astrocytic tumours is vast if compared to 20 years ago, yet we are far from understanding the details of this process at the molecular level and using such an understanding to logically and specifically treat patients' tumours. In other astrocytic tumours we have little or no knowledge of the molecular processes. This article will attempt to summarise the histological classification criteria and genetic data for all the astrocytic tumours. The current World Health Organisation classification lists six entities, some with subgroups. Common problems associated with the diagnosis of these tumours are outlined. While the molecular findings are not as yet used clinically, we are approaching a time when the histological investigation will have to be supplemented with molecular data to ensure the best choice of treatment for the patient and as an accurate indicator of prognosis.