Von Recklinghausen's neurofibromatosis: neurofibromatosis type 1

The mutational spectrum of the NF1 gene in neurofibromatosis type I patients from UAE

INTRODUCTION

Germline heterozygous mutations in the tumor suppresser NF1 gene cause a cancer predisposition syndrome known as neurofibromatosis type 1 (NF1). This disease is one of the most common multisystem disorders with an estimated incidence of 1 in 3,000 to 1 in 4,000 births. Clinically, NF1 patients are prone to develop "café au lait" spots, neurofibromas, Lisch nodules, freckling of the axillary, or inguinal region and optic nerve gliomas.

MATERIALS AND METHODS

In the present study, we report clinical and molecular findings of five unrelated patients and seven cases from four families with NF1 from UAE. To reveal the genetic defects underlying NF1 in our cohort of patients, we screened the whole coding and splice site regions of the NF1 gene. In addition, MLPA or CGH array has been used to screen for structural variations including deletions, indels, and complex rearrangements.

RESULTS

This resulted in the identification of five distinct novel mutations and two previously reported ones. These variations included three missense and one nonsense mutations, one single base, one dinucleotide, and one large deletion.

CONCLUSION

Four mutations were inherited, and the remaining were absent from both parents and therefore are "de novo" mutations. This analysis represents the spectrum of NF1 mutations in UAE and supports the premise of absence of hotspot mutations in the NF1 gene. Moreover, no obvious genotype-phenotype correlations were observed in our patients.

Neurodermatology

Since the skin and the central and/or peripheral nervous system share a common source (the ectoderm), numerous genetic and acquired diseases (infectious, tumoral or autoimmune disorders) equally affect both. Neurologic diseases or symptoms such as stroke, cerebral or medullary vascular malformations, peripheral, brain or medullary tumors, epilepsy, ataxia, neurologic infections, or cognitive disorders (dementia, mental retardation) may be associated with specific cutaneous manifestations of which the discovery can facilitate the final diagnosis, thereby leading to specific treatment and/or genetic investigations. Careful examination of the skin, hair, and nails by the neurologist is consequently of the utmost importance; when unusual abnormalities of the skin are discovered or when greater expertise is required, consultation with a dermatologist is frequently advisable.

Renal artery stenosis due to neurofibromatosis type 1: case report and literature review

Background

Neurofibromatosis type 1 (NF1) is a relatively common autosomal dominant disorder. The most common vascular abnormality in patients with NF1 is bilateral or unilateral renal artery stenosis.

Case report

A 16-year-old boy presented with a headache of 4-year duration and was found to be moderately hypertensive. On physical examination, axillary freckling and multiple café-au-lait spots were revealed over the trunk, while numerous small nodules were palpable on the limbs. Biopsy of subcutaneous nodule showed neurofibroma. Lisch nodules were identified on slit-lamp examination and grade I hypertensive retinopathy was present on fundoscopy. Clinical laboratory investigations revealed that renal and liver function tests, blood cells count, urinalysis, serum electrolytes, serum levels of renin and aldosterone, and 24-hour urine levels of catecholamines were all within normal ranges. Abdominal ultrasound and CT were normal. Both kidneys were of normal size. CT angiography showed right renal artery stenosis (>90%) at the ostium. The final diagnosis of NF1 with right renal artery stenosis and secondary hypertension was then made. The patient was treated with Procardin (30 mg/d) and improved with a significant decline in blood pressure. The main outcomes were to control blood pressure without necessarily proceeding with PTRA. We also present a review of the literature.

Conclusions

NF1 may present with hypertension due to renal artery stenosis in children. All young patients (<30 year) with hypertension should be clinically screened for secondary causes of hypertension, including NF1, so that renal revascularization can be offered before permanent end organ damage has occurred. First-line management using medication alone could be appropriate, keeping the interventional options for when the patient's condition deteriorates.

Patient affected by neurofibromatosis type 1 and thyroid C-cell hyperplasia harboring pathogenic germ-line mutations in both NF1 and RET genes

Neurofibromatosis type 1 (NF1) is a rare autosomal dominant disease with an estimated incidence of 1 in 3000/3500 live births. NF1 is caused by a mutation in a gene which encodes a protein known as neurofibromin. In up to 5% of cases, NF1 is associated with pheochromocytomas. RET proto-oncogene encodes a member of the receptor tyrosine kinase family involved in the normal development or the neoplastic growth of neural crest cell lineages. Germ-line RET mutations account for cases of Multiple Endocrine Neoplasia type 2 (MEN2), an autosomal dominant genetic syndrome where medullary thyroid carcinoma (MTC) is the major and more clinically severe feature, with nearly complete penetrance. C-cell hyperplasia (CCH) is described in MEN2 patients, and it has been implicated as the precursor of in situ MTC. Patients with RET mutations develop pheochromocytomas in 50% of cases. Rarely, patients with NF1 have been found to present, in addition to the NF1 clinical picture, other lesions, such as parathyroid hyperplasia/adenoma and/or medullary thyroid carcinoma. In spite of the presence of these MEN2 lesions, in none of these patients mutations of gene RET have been found so far. In this report, we describe the first case of a patient affected by a germ-line mutation in both NF1 and RET genes.

World Health Organization group 5 pulmonary hypertension

World Health Organization (WHO) group 5 pulmonary hypertension (PH) entails a heterogeneous group of disorders that may cause PH by unclear and/or multiple mechanisms. In particular, group 5 includes PH caused by hematologic disorders, systemic diseases, metabolic disorders, chronic renal failure, and disorders leading to pulmonary vascular occlusion or compression. This article discusses common pathogenic mechanisms leading to group 5 PH, followed by a detailed overview of epidemiology, pathogenesis, and disease-specific management of the individual group 5 conditions. Off-label use of vasomodulatory therapies, typically indicated for pulmonary arterial hypertension (WHO group 1 PH), in group 5 conditions is also discussed.

Lymphangiopathy in neurofibromatosis 1 manifesting with chylothorax, pericardial effusion, and leg edema

Background

This case report documents the affliction of the lymph vessels as a phenotypic feature of neurofibromatosis-1 (NF-1).

Methodology

Routine transthoracic echocardiography, computed tomography scan of the thorax, magnetic resonance angiography of the renal arteries, and conventional digital subtraction angiography were applied. Comprehensive NF-1 mutation analysis was carried out by fluorescence in situ hybridization analysis, long-range reverse transcriptase polymerase chain reaction, and multiple-ligation probe assay. All other investigations were performed using routine, well-established techniques.

Results

The subject is a 34-year-old, half-Chinese male; NF-1 was suspected at age 15 years for the first time. His medical history included preterm birth, mild facial dysmorphism, “café au lait” spots, subcutaneous and paravertebral fibromas, multifocal tachycardia, atrial fibrillation, and heart failure in early infancy. Noncalcified bone fibromas in the femur and tibia were detected at age 8 years. Surgical right leg lengthening was carried out at age 11 years. Bilateral renal artery stenosis, stenosis and aneurysm of the superior mesenteric artery, and an infrarenal aortic stenosis were detected at age 15 years. Leg edema and ectasia of the basilar artery were diagnosed at age 18 years. After an episode with an erysipela at age 34 years, he developed pericardial and pleural effusion during a 4-month period. Stenosis of the left subclavian vein at the level of thoracic duct insertion was detected. After repeated pleural punctures, pleural effusion was interpreted as chylothorax. Reduction of lymph fluid production by diet and injection of talcum into the pleural cavity had a long-term beneficial effect on the chylothorax. Leg edema and chylothorax were attributed to affliction of the lymph vessels by the NF-1.

Discussion

Lymphangiopathy resulting in impaired lymph fluid flow and sequestration of lymph fluid into the pleural sinus and the legs may be a rare phenotypic feature of NF-1.

Neurofibromatosis-1 gene deletions and mutations in de novo adult acute myeloid leukemia

Germline heterozygous alterations of the tumor-suppressor gene neurofibromatosis-1 (NF1) lead to neurofibromatosis type 1, a genetic disorder characterized by a higher risk to develop juvenile myelomonocytic leukemia and/or acute myeloid leukemia (AML). More recently, somatic 17q11 deletions encompassing NF1 have been described in many adult myeloid malignancies. In this context, we aimed to define NF1 involvement in AML. We screened a total of 488 previously untreated de novo AML patients for the NF1 deletion using either array comparative genomic hybridization (aCGH) or real-time quantitative PCR/fluorescence in situ hybridization approaches. We also applied massively parallel sequencing for in depth mutation analysis of NF1 in 20 patients including five NF1-deleted patients. We defined a small ∼0.3 Mb minimal deleted region involving NF1 by aCGH and an overall frequency of NF1 deletion of 3.5% (17/485). NF1 deletion is significantly associated with unfavorable cytogenetics and with monosomal karyotype notably. We discovered six NF1 variants of unknown significance in 7/20 patients of which only one out of four disappeared in corresponding complete remission sample. In addition, only one out of five NF1-deleted patients has an acquired coding mutation in the remaining allele. In conclusion, direct NF1 inactivation is infrequent in de novo AML and may be a secondary event probably involved in leukemic progression.

Cerebral vasculopathy in children with neurofibromatosis type 1

Cerebral vasculopathy is an important but underrecognized complication of neurofibromatosis type 1. Over a 10-year period, we retrospectively assessed the prevalence, clinical manifestations, management, and outcome of cerebral vasculopathy in children with neurofibromatosis type 1. Magnetic resonance imaging (MRI) of the brain was performed on 78% of the patients (312/398) of which 46% (143/312) had magnetic resonance angiography of the intracranial arteries; 4.8% (15/312) had cerebral vasculopathy. Approximately half were asymptomatic at presentation; none had neurologic deficits. Cerebral vasculopathy included moyamoya changes (7) and stenosis/occlusion of major intracranial arteries (8). On follow-up (mean 4 years), 2 patients developed radiologic progression; 1 was treated with aspirin alone, whereas another underwent revascularization surgery. Although cerebral vasculopathy in neurofibromatosis type 1 may be asymptomatic at presentation, there may be radiologic and clinical progression leading to morbidity and mortality. Magnetic resonance angiography should be considered with brain MRI for early detection and timely intervention of cerebral vasculopathy.

The eye and phacomatoses

This article reviews the ocular and neuro-opthalmic manifestations of phacomatoses, while emphasizing important differential diagnoses that exist based on their clinical features. Variations in the definition of phacomatoses do exist, but conditions not meeting the classical definition are also presented.

Myeloproliferative neoplasms: from JAK2 mutations discovery to JAK2 inhibitor therapies

Most BCR-ABL1-negative myeloproliferative neoplasms (MPN) carry an activating JAK2 mutation. Approximately 96% of patients with polycythemia vera (PV) harbors the V617F mutation in JAK2 exon 14, whereas the minority of JAK2 (V617F)-negative subjects shows several mutations in exon 12. Other mutation events as MPL, TET2, LNK, EZH2 have been described in chronic phase, while NF1, IDH1, IDH2, ASX1, CBL and Ikaros in blast phase of MPN. The specific pathogenic implication of these mutations is under investigation, but they may have a role in refinement of diagnostic criteria and in development of new prognostic models. Several trials with targeted therapy (JAK inhibitors) are ongoing mostly involving patients with PMF, post-PV MF and post-essential thrombocythemia (ET) MF. Treatment with ruxolitinib and TG101348 has shown clinically significant benefits, particularly in improvement of splenomegaly and constitutional symptoms in MF patients. On the other hand, JAK inhibitors have not thus far shown disease-modifying activity therefore any other deduction on these new drugs seems premature.

Intraspinal primitive neuroectodermal tumor in a man with neurofibromatosis type 1: Case report and review of the literature

BACKGROUND

The occurrence of primitive neuroectodermal tumors (PNET) in patients with neurofibromatosis type 1 (NF1) has only been reported in two other cases in English-Language literature. Owing to the rarity of intraspinal PNET and the extremely high gene mutation variability in NF1, there is currently no conclusive evidence to suggest that PNET is associated with NF1. Here, we report a case of intradural PNET in a patient with NF1.

CASE DESCRIPTION

A 27-year-old male underwent a C1-C3 laminectomy for resection of an intramedullary mass. Histopathology and immunohistopathology analysis was performed. Microscopic examination and immunohistochemical staining indicated the mass was a primitive neuroectodermal tumor. Within 1 month after tumor resection, the patient developed leptomeningeal carcinomatosis. The patient was not a candidate for radiation therapy but underwent palliative systemic chemotherapy. He subsequently developed neutropenia and died 3 months after tumor resection.

CONCLUSION

To our knowledge, this is the first reported intraspinal PNET associated with NF1. Genetic analysis of CNS PNETs suggests a possible correlation, but larger case series are needed to support this theory.

Pulmonary hypertension in patients with neurofibromatosis type I

Neurofibromatosis type I (NF1) is a rare genetic disease caused by mutations in the NF1 gene, which codes for tumor suppressor neurofibromin. NF1 is transmitted as an autosomal dominant and fully penetrant trait with no sex predominance. Precapillary pulmonary hypertension (PH) is a severe complication of NF1, initially described in patients with advanced parenchymal lung disease, which may complicate the course of NF1. We conducted this study to describe clinical, functional, radiologic, and hemodynamic characteristics and outcome of patients with NF1-associated PH. We identified 8 new cases of NF1-associated PH in patients carrying a NF1 gene mutation. No bone morphogenic protein receptor 2 (BMPR2) point mutation or large size rearrangements were identified. Seven female patients and 1 male patient were reported, suggesting a possible female predominance. PH occurred late in the course of the disease (median age, 62 yr; range, 53-68 yr). Dyspnea and signs of right heart failure were the major symptoms leading to the diagnosis of PH. At diagnosis, patients had severe hemodynamic impairment with low cardiac index (median, 2.3 L/min per m2; range, 1.9-4.7) and elevated indexed pulmonary vascular resistance (median, 15.1 mm Hg/L/min per m2; range, 4.5-25.9). All patients were in New York Heart Association functional class III with severe exercise limitation (median 6-min walk distance, 180 m; range, 60-375 m). Most patients had associated parenchymal lung disease, but some had no or mild lung involvement with disproportionate pulmonary vascular disease. Overall, the impact of PH therapy was limited and outcomes were poor. In conclusion, PH represents a rare but severe complication of NF1, characterized by female predominance, late onset in the course of NF1, and severe functional and hemodynamic impairment. Because of poor outcome and limited impact of specific PH therapy, eligible patients require early referral for lung transplantation. Further studies are needed to better understand the pathophysiology and the role, if any, of neurofibromin in NF1-associated PH.

Ras and Rap signaling in synaptic plasticity and mental disorders

The Ras family GTPases (Ras, Rap1, and Rap2) and their downstream mitogen-activated protein kinases (ERK, JNK, and p38MAPK) and PI3K signaling cascades control various physiological processes. In neuronal cells, recent studies have shown that these parallel cascades signal distinct forms of AMPA-sensitive glutamate receptor trafficking during experience-dependent synaptic plasticity and adaptive behavior. Interestingly, both hypo- and hyperactivation of Ras/ Rap signaling impair the capacity of synaptic plasticity, underscoring the importance of a "happy-medium" dynamic regulation of the signaling. Moreover, accumulating reports have linked various genetic defects that either up- or down-regulate Ras/Rap signaling with several mental disorders associated with learning disability (e.g., Alzheimer's disease, Angelman syndrome, autism, cardio-facio-cutaneous syndrome, Coffin-Lowry syndrome, Costello syndrome, Cowden and Bannayan-Riley-Ruvalcaba syndromes, fragile X syndrome, neurofibromatosis type 1, Noonan syndrome, schizophrenia, tuberous sclerosis, and X-linked mental retardation), highlighting the necessity of happy-medium dynamic regulation of Ras/Rap signaling in learning behavior. Thus, the recent advances in understanding of neuronal Ras/Rap signaling provide a useful guide for developing novel treatments for mental diseases.

Hereditary genodermatoses with cancer predisposition

In this article hereditary genodermatoses with cancer predisposition are reviewed, including nevoid basal cell carcinoma syndrome, neurofibromatosis types 1 and 2, tuberous sclerosis complex, xeroderma pigmentosum, and dyskeratosis congenita. Hereditary melanoma is also included, though it differs from the others in several respects. The underlying genetic aberrations causing these syndromes are largely known, allowing novel treatments to be developed for some of these disorders. Early recognition and diagnosis allows for close follow-up and surveillance for associated malignancies.

Sonographic findings in a patient with neurofibromatosis type 1 and a gastrointestinal stromal tumor

Gastrointestinal stromal tumors (GIST) have been suggested to be the most common neurofibromatosis 1-associated gastrointestinal tumors. This case report describes and compares US and CT findings of both abdominal neurofibromas and a gastrointestinal stromal tumor. On US, the GIST appeared as a well-defined inhomogeneous lesion with a target-like pattern similar to CT. The neurofibromas appeared as well-demarcated round nodules with a relatively homogeneous hypoechoic internal structure and were accompanied by subtle posterior acoustic enhancement. US and CT were able to differentiate between neurofibromatomas and GIST in this neurofibromatosis 1 patient; however, a biopsy of the suspicious mass was performed to clarify the diagnosis.

Safe performance of spinal anesthesia in a critical patient with neurofibromatosis, pectus carinatum, and temporomandibular joint dysfunction: A case report

BACKGROUND

Neurofibromatosis is a syndrome caused by the abnormal deposition of neural tissues of the nervous system, endocrine system, visceral structures, and skin. On the other hand, pectus carinatum and temporomandibular joint dysfunction are illnesses that adversly affect the respiratory system and cause additional problems in airway management.

CASE PRESENTATION

Fifty-eight-year-old Turkish male patient had neurofibromatosis, pectus carinatum and temporomandibular joint dysfunction. The case was due to be operated on with the diagnosis of incarcerated umbilical hernia. Spinal anesthesia was successfully performed and the duration of the surgery was 1 hour. No postoperative complications were observed and he was discharged from the hospital on the 3rd post-operative day.

CONCLUSION

The anesthetic management of patients with neurofibromatosis requires attention to all possible abnormalities and associated disturbances. Furthermore, the presence of pectus carinatum and temporomandibular joint dysfunction also increase the potential risks. The operation was successfully completed with spinal anesthesia that was carefully applied upon taking the required measures and considering all pathologies that may accompany the case and complications that may occur.

The association between autism and errors in early embryogenesis: what is the causal mechanism?

The association between embryonic errors and the development of autism has been recognized in the literature, but the mechanism underlying this association remains unknown. We propose that pleiotropic effects during a very early and specific stage of embryonic development-early organogenesis-can explain this association. In humans early organogenesis is an embryonic stage, spanning Day 20 to Day 40 after fertilization, which is characterized by intense interactivity among body parts of the embryo. This implies that a single mutation or environmental disturbance affecting development at this stage can have several phenotypic effects (i.e., pleiotropic effects). Disturbances during early organogenesis can lead to many different anomalies, including limb deformities, craniofacial malformations, brain pathology, and anomalies in other organs. We reviewed the literature and found ample evidence for the association between autism and different kinds of physical anomalies, which agrees with the hypothesis that pleiotropic effects are involved in the development of autism. The proposed mechanism integrates findings from a variety of studies on autism, including neurobiological studies and studies on physical anomalies and prenatal influences on neurodevelopmental outcomes. The implication is that the origin of autism can be much earlier in embryologic development than has been frequently reported.

High-resolution single-nucleotide polymorphism array-profiling in myeloproliferative neoplasms identifies novel genomic aberrations

Single-nucleotide polymorphism arrays allow for genome-wide profiling of copy-number alterations and copy-neutral runs of homozygosity at high resolution. To identify novel genetic lesions in myeloproliferative neoplasms, a large series of 151 clinically well characterized patients was analyzed in our study. Copy-number alterations were rare in essential thrombocythemia and polycythemia vera. In contrast, approximately one third of myelofibrosis patients exhibited small genomic losses (less than 5 Mb). In 2 secondary myelofibrosis cases the tumor suppressor gene NF1 in 17q11.2 was affected. Sequencing analyses revealed a mutation in the remaining NF1 allele of one patient. In terms of copy-neutral aberrations, no chromosomes other than 9p were recurrently affected. In conclusion, novel genomic aberrations were identified in our study, in particular in patients with myelofibrosis. Further analyses on single-gene level are necessary to uncover the mechanisms that are involved in the pathogenesis of myeloproliferative neoplasms.

A patient with loss of vision in the right eye and neurofibromatosis type 1

Neurofibromatosis type 1 is a common autosomal dominant condition that affects about 1 in 5000 people. We describe a 75-year-old man who, in addition to many classic developmental changes of the disease in his skin, eyes and nervous system, had blindness in his right eye as a complication.

Neurofibromatosis type 1 revisited

Neurofibromatosis type 1 (NF1) is an autosomal dominant condition with a worldwide incidence of approximately 1 per 2500 to 3000 individuals. Caused by a germ-line-inactivating mutation in the NF1 gene on chromosome 17, the disease is associated with increased morbidity and mortality. In the past several years, significant progress has been made in standardizing management of the major clinical features of neurofibromatosis type 1. Moreover, improved understanding of how the neurofibromatosis type 1 protein, neurofibromin, regulates cell growth recently provided insight into the pathogenesis of the disease and has led to the development of new therapies. In this review, we describe the clinical manifestations, recent molecular and genetic findings, and current and developing therapies for managing clinical problems associated with neurofibromatosis type 1.

A malignant peripheral nerve sheath tumor of the mediastinum in a patient with neurofibromatosis type 1: report of a case

Malignant peripheral nerve sheath tumor (MPNST) is rare, but its association with neurofibromatosis type 1 (NF1) is well known. A 56-year-old man with NF1 was referred to our hospital for investigation of dyspnea. Computed tomography showed a huge mass occupying the right thorax and invading the inferior vena cava. A salvage resection was performed to alleviate the developing hypoxemia. Histological examination confirmed an MPNST. The tumor regrew rapidly and the patient died 6 weeks after the resection. This case report reinforces the importance of monitoring patients with NF1 carefully because of their increased risk of the development of malignant neoplasms.

Extra-intestinal manifestations of familial adenomatous polyposis

Familial adenomatous polyposis (FAP) is an autosomal dominantly inherited disorder, which results from a germ line mutation in the APC (adenomatous polyposis coli) gene. FAP is characterized by the formation of hundreds to thousands of colorectal adenomatous polyps. Although the development of colorectal cancer stands out as the most prevalent complication, FAP is a multisystem disorder of growth. This means, it is comparable to other diseases such as the MEN syndromes, Von Hippel-Lindau disease and neurofibromatosis. However, the incidence of many of its clinical features is much lower. Therefore, a specialized multidisciplinary approach to optimize health care-common for other disorders-is not usually taken for FAP patients. Thus, clinicians that care for and counsel members of high-risk families should have familiarity with all the extra-intestinal manifestations of this syndrome. FAP-related complications, for which medical attention is essential, are not rare and their estimated lifetime risk presumably exceeds 30%. Affected individuals can develop thyroid and pancreatic cancer, hepatoblastomas, CNS tumors (especially medulloblastomas), and various benign tumors such as adrenal adenomas, osteomas, desmoid tumors and dental abnormalities. Due to improved longevity, as a result of better prevention of colorectal cancer, the risk of these clinical problems will further increase. We present a clinical overview of extra-intestinal manifestations, including management and treatment options for the FAP syndrome. Furthermore, we provide recommendations for surveillance of FAP complications based on available literature.

Neurofibroma of the porta hepatis

Neurofibromas are generally well-circumscribed tumors of the nervous system, often found in association with neurofibromatosis 1 (NF1). They uncommonly present as a single sporadic form in the retroperitoneum and in the pancreas. We present a case of a 40-year-old man who presented with a 4- to 5-year history of right upper quadrant pain with associated nausea and vomiting. Medical imaging showed a 3.8 by 3.4-cm mass encasing the hepatic artery and the porta hepatis. Surgical resection was performed, with removal of the gallbladder. The mass was histologically diagnosed as a neurofibroma. At 1 year following his surgery, the patient is doing well.

DNA profiling analysis of 100 consecutive de novo acute myeloid leukemia cases reveals patterns of genomic instability that affect all cytogenetic risk groups

We have carried out a high-resolution whole genome DNA profiling analysis on 100 bone marrow samples from a consecutive series of de novo acute myeloid leukemia (AML) cases. After discarding copy number changes that are known to be genetic polymorphisms, we found that genomic aberrations (GA) in the form of gains or losses of genetic material were present in 74% of the samples, with a median of 2 GA per case (range 0-35). In addition to the cytogenetically detected aberration, GA were present in cases from all cytogenetic prognostic groups: 79% in the favorable group, 60% in the intermediate group (including 59% of cases with normal karyotype) and 83% in the adverse group. Five aberrant deleted regions were recurrently associated with cases with a highly aberrant genome (e.g., a 1.5 Mb deletion at 17q11.2 and a 750 kb deletion at 5q31.1). Different degrees of genomic instability showed a statistically significant impact on survival curves, even within the normal karyotype cases. This association was independent of other clinical and genetic parameters. Our study provides, for the first time, a detailed picture of the nature and frequency of DNA copy number aberrations in de novo AML.

Orbital Embryonal Rhabdomyosarcoma in Association with Neurofibromatosis Type 1

A 20-month-old child with systemic features of neurofibromatosis type 1 presented with sudden-onset proptosis. Biopsy and histopathology confirmed the diagnosis of an embryonal rhabdomyosarcoma. The tumor regressed completely with chemotherapy and external beam radiotherapy. This case highlights the association of rhabdomyosarcoma with neurofibromatosis type 1.

Type 1 neurofibromatosis complicated by pulmonary artery hypertension: a case report

We describe the case of a patient with neurofibromatosis type 1 (NF1) complicated by severe pulmonary aterial hypertension (PAH); only seven cases have been reported on this association so far, and PAH seems to be related to the vascular involvement of neurofibromatosis. The histology of our patient's lung tissue showed thickening of arteries and veins by medial and/or intimal hypertrophy and fibrosis. In order to exclude a familiar PAH, the analysis of the bone morphogenetic protein receptor 2 gene was carried out, but no mutations were found. On the basis of histological findings and of the results of genetic study we believe that PAH was a complication of NF1 in our patient and we suggest to screen patients with NF1 for the presence of PAH by means of trans-thoracic echocardiogram.

[Difficulties of the management of head and neck neurofibromatosis]

INTRODUCTION

Neurofibromatoses represent a group of 7 diseases having the same cutaneous signs due to a common embryologic origin. The types 1 and 2 are the most frequent and the most studied. Neurofibromatosis type 1 (NF1) or Von Recklinghausen's neurofibromatosis is an autosomal dominantly inherited disease, whose prevalence is 1/4500. The cranio-orbitotemporal lesions exist in 1 to 10% of the cases. Neurofibromatosis type 2 (NF2) is also an autosomal dominantly inherited disease, but is ten times less frequent than the NF1 and is characterized by bilateral vestibular schwannomas (former acoustic neurinomas). The purpose of this work was to detail the clinical features, highlighting the diagnostic and therapeutic difficulties.

MATERIAL AND METHODS

Nine patients managed between 1990 and 2005 were reviewed retrospectively. Eight patients were found carrier of NF1 and one patient carrier of NF2 according to the diagnostic criteria of the 1988's National Institute of Health consensus.

RESULTS

Five women and four men were managed; patient age varied between 13 and 62 years and the mean age was 26 years. Surgical resection of the tumor was carried out among 8 patients with bone reconstruction of the orbit on 3 patients and cutaneous expansion on one other. The results are difficult to appreciate especially that the surgery was iterative. However, all our patients were satisfied with the result and we noted recurrence in a patient presenting a retro-auricular tumor, which filled the external auditory canal requiring a further surgery. The patient having NF2 was treated by neurosurgery and showed a good result.

DISCUSSION

The NF1 manifestations are extremely variable. Facial neurofibromatoses are difficult to control given the presence of soft tissues infiltration and the associated osseous dysplasia. The results are modest and recurrence is frequent. Cancer risks and the disease's completely unpredictable evolution urge a regular and multidisciplinary patient follow-up.

Clinically aggressive central giant cell granulomas in two patients with neurofibromatosis 1

BACKGROUND

Neurofibromatosis 1 (NF1) is an autosomal dominantly inherited disorder caused by a spectrum of mutations affecting the Nf1 gene. Affected patients develop benign and malignant tumors at an increased frequency. Clinical findings include multiple cutaneous café-au-lait pigmentations, neurofibromas, axillary freckling, optic gliomas, benign iris hamartomas (Lisch nodules), scoliosis, and poorly defined soft tissue lesions of the skeleton. Kerl first reported an association of NF1 with multiple central giant cell granulomas (CGCGs) of the jaws. There have since been 4 additional published cases of NF1 patients with CGCGs of the jaws.

CLINICAL CASES

We report on 2 patients who presented with NF1 and aggressive CGCGs of the jaws. In both cases, the clinical course was characterized by numerous recurrences despite mechanical curettage and surgical resection.

CONCLUSIONS

We review proposed mechanisms to explain the apparent association between NF1 and an increased incidence of CGCGs of the jaws. While the presence of CGCGs of the jaws in patients with NF1 could represent either a coincidental association or a true genetic linkage, we propose that this phenomenon is most likely related to NF1-mediated osseous dysplasia. Compared to normal bone, the Nf1-haploinsufficient bone in a patient with NF1 may be less able to remodel in response to as of yet unidentified stimuli (e.g. excessive mechanical stress and/or vascular fragility), and consequently may be more susceptible to developing CGCG-like lesions. Alternatively, the CGCG in NF1 patients could represent a true neoplasm, resulting from additional, as of yet unidentified, genetic alterations to Nf1-haploinsufficient bone.

Phaeochromocytoma, new genes and screening strategies

Following recent advances in the genetics of phaeochromocytomas and paragangliomas, the members of the European Network for the Study of Adrenal Tumours (ENS@T) Phaeochromocytoma Working Group have decided to share their genotyping data and to propose European recommendations for phaeochromocytoma/functional paraganglioma (PH/FPGL) genetic testing. Germline DNA from 642 patients was analysed by ENS@T teams. In 166 patients (25.9%) the disease was familial and caused by germline mutations in VHL (56), SDHB (34), SDHD (31), RET (31) or NF1 (14), causing von Hippel-Lindau disease, SDHB- or SDHD-PH/FPGL syndromes, multiple endocrine neoplasia type 2 (MEN 2) and type 1 neurofibromatosis (NF1), respectively. In almost 60% of inherited cases it was possible to formulate a probable genetic diagnosis based on family history and/or typical syndromic presentation. Genetic testing revealed mutations in 12.7% of cases with an apparently sporadic presentation. Several clinical characteristics, such as young age at onset, the presence of bilateral, extra-adrenal or multiple tumours or a malignant tumour, should be seen as indications for genetic testing. The ENS@T Phaeochromocytoma Working Group recommends the genetic testing of all patients with PH and FPGL and suggests a practice algorithm for the management of their exploration.

Sepsis from neurofibromatosis

Neurofibromatosis Type I or von Recklinghausen’s neurofibromatosis is an autosomal dominant disorder with a high index of spontaneous mutations and extremely varied and unpredictable clinical manifestations. We present a case of sepsis secondary to an infected hematoma, enclosed within a massive neurofibroma.

A 42-year-old man presented to the emergency department with a one week history of fever and chills. He reported an increase in pain and size of a growth near his chest. The patient was noted to be febrile on arrival. On physical examination, a very large neurofibroma was seen extending from the right upper chest. Wound and blood cultures were obtained. Computed Tomography (CT) of the thorax revealed a hematoma contained within the large mass.

Tumours of familial origin in the head and neck

Individuals with inherited cancer syndromes are at significant risk of developing both benign and malignant tumours as a result of a germline mutation in a specific tumour suppressor gene. Tumours of familial origin are a rare event in the head and neck but despite this, they deserve a growing interest. Familial paragangliomas are most of the time limited to the paraganglionar system, but also may be part of different syndromic associations. Since early detection of paragangliomas reduces the incidence of morbidity and mortality, genotypic analysis in the search of SDHB, SDHC and SDHD mutations in families of affected patients plays a front-line diagnostic role, leading to more efficient patient management. Multiple endocrine neoplasias type 1 are characterized by the simultaneous occurrence of at least two of the three main related endocrine tumours: parathyroid, enteropancreatic and anterior pituitary. These tumours arise from inactivating germline mutations in the MEN-1 gene. No clear correlation of MEN-1 genotype with genotype has emerged to date, and MEN-1 mutation testing in tumours is not used clinically because it have not implications for tumour staging. Multiple endocrine neoplasia type 2 is due to a germline mutation in the RET proto-oncogene. Hallmarks of MEN-2A (the commonest phenotypic variant) include medullary thyroid carcinoma, pheochromocytoma, and hyperparathyroidism. The most central clinical difference with MEN-1 is that the associated cancer can be prevented or cured by early thyroidectomy in mutation carriers. Individuals with neurofibomatosis type 1 present early in life with pigmentary abnormalities, skinfold freckling and iris hamartomas, as result of NF1 gene mutation. Neurofibromatosis 2 is caused by inactivating mutations of the NF2 gene, and is characterized by the development of nervous system tumours (mainly bilateral vestibular schwannomas), ocular abnormalities, and skin tumours. The molecular genetic basis of nasopharyngeal carcinomas remains unknown, but there is evidence for the linkage of these tumours to chromosome 3p. Finally, the high rate of p16 mutations in squamous cell carcinomas and the association of p16 with familial melanoma propose p16 as an ideal candidate gene predisposing to familial squamous cell carcinomas. The elucidation of the cellular processes affected by dysfunction in familial tumours of the head and neck may serve to identify potential targets for future therapeutic interventions.

Lumbar region intra-spinal primitive neuroectodermal tumour (PNET) combined with neurofibromatosis type 1

Primitive neuroectodermal tumours (PNET) are aggressive neoplasias that are diagnosed, usually, in infancy. Their appearance in adulthood is rare and, exceptionally, in association with neurofibromatosis type I (NF-1). We present a case of a 37 year-old man with NF-1 combined with PNET in the intra-arachidial lumbar region. Diagnosis was by Nuclear Magnetic Resonance (NMR) and biopsy of soft tissue mass which showed a PNET with undifferentiated round cells and immunohistochemically positive for CD99, neurone-specific enolase, synaptophys in and LEU-7. Surgery was performed with spine decompression and resection of 80% of the tumour, with symptoms improvement. Radiotherapy was administered on the lumbosacral column, but only up to 30 Gy because of severe actinic enteritis and pan-cytopenia grade III. Six months later, the patient was hospitalized with deterioration in his overall clinical status with multi-organ involvement. The patient died and an autopsy was performed. The initial treatment of the PNET is surgery and, if possible, the radical extirpation of the tumour. Administration of radiotherapy and chemotherapy appears to increase survival. We comment on the clinical, histological, cytological and immunohistochemical aspects together with a review of the literature. To the best of our knowledge this is the first documentation of such a case.

Neurofibromatosis type I and smoldering multiple myeloma: a case report

We present a case of a 64-year-old woman with neurofibromatosis (NF1) and smoldering multiple myeloma (SMM). SMM was diagnosed 9 years ago when the asymptomatic patient was found to have mild anemia, IgA paraproteinemia, hypogammaglobulinemia, osteopenia without any lytic bone lesions and bone marrow plasmacytosis. During follow-up period she remained stable in an excellent clinical condition without requiring any therapy for almost 4 years. Forty-two months after diagnosis she had a femoral fracture and since then biphosphonates have been administered intravenously, once monthly. Subsequent evaluations of the disease showed a dramatic reduction of IgA paraprotein to below half the initial value. We will discuss the probable pathogenesis of plasma cell dyscrasia in NF1 patients, as well as the likely antimyeloma activity of biphoshonates.

Elephantiasis neuromatosa in neurofibromatosis type I

We report the case of a patient with NF-1 who presented with gross elephantiasis neuromatosa of her right leg. Prior to plastic surgery, Magnetic Resonance Imaging and Angiography (MRI and MRA) were performed to provide a detailed assessment of the extension as well as the vascular and muscular involvement of the neurofibroma.

Obstructive jaundice secondary to neuroendocrine tumour in a patient with von Recklinghausen's disease

Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic disorder, with variable clinical manifestations and unpredictable course, associated with an increased incidence of various tumours. Plexiform neurofibromas are hallmark lesions of NF1; they are slow-growing tumours, which account for substantial morbidity, including disfigurement and functional impairment, and may even be life-threatening. Neuroendocrine tumours (NETs), a rare diverse group of neoplasms, are occasionally associated with neurofibromatosis. Pancreatic NETs are tumours with an incidence of less than 1/100 000 population/year and complex patterns of behaviour, which often need complicated strategies for optimal management. We present the case of a young adult with NF1, having a unique concurrence of plexiform neurofibroma involving the liver with an ampullary NET, and we discuss step by step the management in a specialist centre.

Recurrent retroperitoneal malignant nerve sheath tumor associated with neurofibromatosis type 1 responding to carboplatin and etoposide combined chemotherapy

A 25-year-old man was referred to our hospital with left flank pain, and computed tomography (CT) and magnetic resonance imaging (MRI) revealed large retroperitoneal masses. Physical examination revealed many café-au-lait spots and superficial neurofibromas, and a diagnosis of neurofibromatosis type 1 (von Recklinghausen's disease) was made. The tumor was resected, and the pathological diagnosis was malignant peripheral nerve sheath tumor (MPNST). Six months after the operation, lung metastases were detected. Surgical resection was incomplete, as there were too many lesions. He received four courses of chemotherapy with carboplatin and etoposide, and the metastatic lung lesions were markedly decreased. After chemotherapy, complete resection of the remaining lung lesions was performed, and there has been no recurrence to date.

Solitary colonic neurofibroma in a patient with transient segmental colitis: Case report

Neurofibromas of the large bowel are very rare and usually are part of the colonic involvement in neurofibromatosis type 1 (Nf1, von Recklinghausen’s disease). Solitary neurofibromas of the colon are extremely rare. We describe a case of an isolated neurofibroma that was found in the large bowel of a patient who suffered from segmental colitis and presented with bloody diarrhea. A review of the literature is also included, concerning the disclosure of isolated neurofibromas in the gut and other body parts and the type of gastrointestinal involvement in von Recklinghausen’s disease.

K-ras as a target for cancer therapy

The central role K-, H- and N-Ras play in regulating diverse cellular pathways important for cell growth, differentiation and survival is well established. Dysregulation of Ras proteins by activating mutations, overexpression or upstream activation is common in human tumors. Of the Ras proteins, K-ras is the most frequently mutated and is therefore an attractive target for cancer therapy. The complexity of K-ras signaling presents many opportunities for therapeutic targeting. A number of different approaches aimed at abrogating K-ras activity have been explored in clinical trials. Several of the therapeutic agents tested have demonstrated clinical activity, supporting ongoing development of K-ras targeted therapies. However, many of the agents currently being evaluated have multiple targets and their antitumor effects may not be due to K-Ras inhibition. To date, no selective, specific inhibitor of K-ras is available for routine clinical use. In this review, we will summarize the structure and function of K-ras with attention to its role in tumorigenesis and discuss the successes and failures of the various strategies designed to therapeutically target this important oncogene.