Search Results (11)

Malignant Triton Tumors (MTTs) are rare, high-grade malignant peripheral nerve sheath tumors (MPNSTs) frequently associated with Type 1 Neurofibromatosis (NF1). NF1, an autosomal dominant disorder, predisposes approximately 10% of affected individuals to developing MPNSTs, with 50% of these tumors occurring in NF1 patients, while others arise sporadically or in association with radiation exposure. MTTs predominantly affect anatomical regions rich in large nerves, such as the limbs, spinal root, and cranial nerves. Mediastinal presentations are exceedingly rare, posing significant diagnostic and therapeutic challenges. Current treatment strategies include surgical resection, chemotherapy, radiotherapy, and lung-sparing procedures for metastatic disease. Molecular studies of MPNSTs have revealed that NF1 mutations lead to dysregulation of the RAS signalling pathway, while epigenetic alterations (e.g., SUZ12/EED mutations) further contribute to tumor progression. Dysregulated phylogenetically conserved pathways, including Wnt/beta-catenin and non-canonical SHH signalling, play a role in sarcoma progression and Schwann cell transformation. Recent advances in miRNA research highlight their involvement in tumor invasion and progression, with dysregulated miRNA expression and chromatin remodeling contributing to the pathogenesis of these neoplasms. However, the distinct molecular profiles for MTTs remain incompletely understood. Further investigation of the genetic and epigenetic landscape is essential for improving our understanding and identifying potential therapies. Herein, we present a single-center retrospective case series of three patients with an intrathoracic triton tumor treated at our University Hospital between 2000 and 2024, serving as a starting point for future insights into MPNST pathobiology. Full article

Neurofibromatosis is a genetic disorder arising de novo or with an autosomal dominant transmission that typically presents either at birth or in early childhood, manifesting through distinctive clinical features such as multiple café-au-lait spots, benign tumors in the skin, bone enlargement, and deformities. This literature review aims to resume the spectrum of maternal and fetal complications encountered in pregnant women with neurofibromatosis type 1 (NF1). Thorough research was conducted on databases such as Web of Science, PubMed, Science Direct, Google Scholar, and Wiley Online Library. This review includes 48 case reports, original studies, and reviews on NF1 in pregnancy. The research on the interlink between NF1 and fertility and its influence on human-assisted reproduction techniques is limited. Preimplantation testing (by in vitro fertilization) and prenatal diagnosis (by chorionic villus sampling or amniocentesis) are available to detect affected fetuses. However, genotype–phenotype correlation is difficult to predict. Preconceptional planning and targeted investigations are crucial in understanding the extent of maternal disease. Although in some cases lesions can evolve rapidly during pregnancy, most pregnancies and births in NF1 go well with careful planning. There is a higher incidence of pheochromocytomas and pre-eclampsia, vascular rupture, and cardio-respiratory issues. Anesthesia at birth is a challenge in most cases, and before offering spinal anesthesia, imaging tests should be performed to characterize spinal lesions. General anesthesia may also be challenging when the disease affects the face, neck, upper spine, or airways. Birth-related difficulties may arise because of large neurofibromas located at the level of skin incision or birth canal; uterine atony may be expected if there are uterine lesions. Some complications can develop in postpartum, and affected women should be carefully followed even after pregnancy. Fetal risks include preterm birth (spontaneous or iatrogenic), growth restriction and developmental issues, birth complications, cardiovascular risk, and fetal/neonatal demise. Pregnancies in women with NF1 should be regarded as high-risk and followed in a multidisciplinary fashion. Careful assessment of lesions is of utmost importance before and during pregnancy for anticipating potential maternal risks and before birth to plan anesthesia and delivery. Full article

Background/Objectives: Surgery for adolescent idiopathic deformities is often aimed at improving aesthetic appearance, striving for the best possible correction. However, severe and rigid scoliotic curves not only present aesthetic issues but can also compromise cardiopulmonary health and cause early neurological impairment due to spinal cord compression, posing significant risks of morbidity and mortality if untreated. Conservative treatments are ineffective for severe curves, defined by scoliotic angles over 70° and flexibility below 30% on lateral bending X-rays. Treatment often requires invasive interventions, such as osteotomies and vertebral resections. In particular, posterior vertebral column resection (PVCR) has shown effectiveness in realigning vertebral structures in complex cases. This study describes the efficacy and risks of PVCR through a series of cases treated at our institution. Methods: This case series was conducted at the Rizzoli Orthopedic Institute in Bologna, involving eight pediatric patients with severe, rigid spinal deformities, operated upon between 2018 and 2023. The underlying pathologies included idiopathic kyphoscoliosis, neurofibromatosis type 1, Pott’s disease, and other congenital anomalies. Preoperative assessment included standard radiographs, magnetic resonance imaging, and computed tomography. During PVCR, motor and sensory evoked potentials were monitored to minimize neurological injury risk. Postoperative management included blood transfusions, antibiotic support, and early physiotherapy. Results: PVCR resulted in an average reduction in the Cobb angle from 86.3° preoperatively to 22.4° postoperatively, with a mean correction of 64%. The mean duration of the procedures was 337.4 min. Three patients had an uneventful postoperative course, while five developed complications, including infections and temporary neurological deficits, which were successfully managed. One patient developed an epidural hemorrhage that required emergency surgery for hematoma evacuation, with partial recovery. This study demonstrates the potential of PVCR for correcting rigid spinal deformities, highlighting the importance of postoperative management to minimize the associated risks. Conclusions: Posterior vertebral resection techniques offer significant promise in the correction of pediatric spinal deformities. Although ours is a small case series, it can provide important data for such treatment. Long-term monitoring is needed to fully understand the impact of these procedures and to further refine surgical techniques. Full article

Background: The management of spinal deformities in patients with NF-1 is challenging. The study aimed to assess the outcomes of the surgical treatment of spine deformities in children with neurofibromatosis type 1 with our treatment approach. Methods: A retrospective single-center study on pediatric patients with spinal deformities associated with NF-1 who received surgical treatment between 2006 and 2024. Results: The study group comprised 42 patients with a mean age at surgery of 9.8 years. Twenty-five patients (60%) were treated by means of growth-preserving techniques and 17 patients (40%) by means of definitive fusion. Preoperative halo-gravity traction was used in 14 (33%) cases. In the group treated with a growth-preserving technique, a 54.1% mean curve correction was observed at the latest follow-up, and growth of the thoracic spine was maintained at a physiological rate; however, 25 unplanned revision surgeries (mostly due to mechanical complications) were necessary. In the group treated by definitive fusion, a 66% curve correction was achieved at initial surgery, which remained unchanged at latest follow-up, and revision surgery was performed in three cases for augmentation of the fusion mass. There was one neurological complication (2%). Another patient developed a deep wound infection (2%). Conclusions: Good and sustainable surgical correction of spinal deformities can be achieved in pediatric patients with NF-1. Due to the bony dystrophic changes, surgical treatment is challenging and the complication rate is higher than in spinal deformities of other etiologies. Full article

Neurofibromatosis type 1 (NF1) is an autosomal dominant neurocutaneous disorder caused by loss-of-function variants in the NF1 gene. As of 20 November 2023, over 5000 distinct pathogenic or likely pathogenic variants have been reported in public databases. However, only a few NF1 genotype–phenotype correlations have been established so far. In this study, we present findings on 40 individuals with NF1, comprising 26 unrelated probands and 14 affected relatives, who carry one of nine NF1 heterozygous pathogenic splicing variants, all of which result in the in-frame skipping of exon 24 [19a] (NM_000267.3:r.3114_3197del, p.Asn1039_Arg1066del). These variants include c.3114-2A>G, c.3114-1G>A, c.3196A>G, c.3197G>A, c.3197G>T, c.3197+1G>A, c.3197+1G>T, c.3197+2T>C, and c.3197+3A>T. Among individuals with these variants, none exhibit externally visible plexiform neurofibromas, histopathologically confirmed cutaneous or subcutaneous neurofibromas, symptomatic spinal neurofibromas, or symptomatic optic pathway gliomas. The most prevalent, and sometimes sole, clinical feature observed in this cohort is multiple café-au-lait macules, with or without skinfold freckles: 85% and 60.5% of the individuals display six or more café-au-lait macules and freckles, respectively. In comparison to established NF1 genotype–phenotype correlations, these patients demonstrate highly similar clinical presentations to those associated with the NF1 pathogenic variant c.2970_2972del (p.Met992del), known for resulting in the mildest clinical features. Despite the generally mild phenotype, cognitive impairment, developmental delay, and/or learning difficulties are still observed in 33.3% of these patients, suggesting that learning challenges remain a prominent aspect of the phenotypic presentation in these individuals and necessitate specialized care. This newly established genotype–phenotype correlation will assist clinicians in improving the management of patients harboring NF1 exon 24 [19a] skipping variants and provide a new therapeutic target for NF1 treatment. Full article

Spinal neurofibromatosis (SNF), a phenotypic subclass of neurofibromatosis 1 (NF1), is characterized by bilateral neurofibromas involving all spinal roots. In order to deepen the understanding of SNF’s clinical and genetic features, we identified 81 patients with SNF, 55 from unrelated families, and 26 belonging to 19 families with at least 1 member affected by SNF, and 106 NF1 patients aged >30 years without spinal tumors. A comprehensive NF1 mutation screening was performed using NGS panels, including NF1 and several RAS pathway genes. The main features of the SNF subjects were a higher number of internal neurofibromas (p < 0.001), nerve root swelling (p < 0.001), and subcutaneous neurofibromas (p = 0.03), while hyperpigmentation signs were significantly less frequent compared with the classical NF1-affected cohorts (p = 0.012). Fifteen patients underwent neurosurgical intervention. The histological findings revealed neurofibromas in 13 patients and ganglioneuromas in 2 patients. Phenotypic variability within SNF families was observed. The proportion of missense mutations was higher in the SNF cases than in the classical NF1 group (21.40% vs. 7.5%, p = 0.007), conferring an odds ratio (OR) of 3.34 (CI = 1.33–10.78). Two unrelated familial SNF cases harbored in trans double NF1 mutations that seemed to have a subclinical worsening effect on the clinical phenotype. Our study, with the largest series of SNF patients reported to date, better defines the clinical and genetic features of SNF, which could improve the management and genetic counseling of NF1. Full article

Neurofibromatosis type 1 (NF1), which is the most common phacomatoses, is an autosomal dominant disorder characterized by clinical presentations in various tissues and organs, such as the skin, eyes and nervous and skeletal systems. The musculoskeletal implications of NF1 include a variety of deformities, including scoliosis, kyphoscoliosis, spondylolistheses, congenital bony bowing, pseudarthrosis and bone dysplasia. Scoliosis is the most common skeletal problem, affecting 10–30% of NF1 patients. Although the pathophysiology of spinal deformities has not been elucidated yet, defects in bone metabolism have been implicated in the progression of scoliotic curves. Measurements of Bone Mineral Density (BMD) in the lumbar spine by using dual energy absorptiometry (DXA) and quantitative computer tomography (QCT) have demonstrated a marked reduction in Z-score and osteoporosis. Additionally, serum bone metabolic markers, such as vitamin D, calcium, phosphorus, osteocalcin and alkaline phosphatase, have been found to be abnormal. Intraoperative and histological vertebral analysis confirmed that alterations of the trabecular microarchitecture are associated with inadequate bone turnover, indicating generalized bone metabolic defects. At the molecular level, loss of function of neurofibromin dysregulates Ras and Transforming Growth factor-β1 (TGF-β1) signaling and leads to altered osteoclastic proliferation, osteoblastic activity and collagen production. Correlation between clinical characteristics and molecular pathways may provide targets for novel therapeutic approaches in NF1. Full article

Complete deletion of the NF1 gene is identified in 5–10% of patients with neurofibromatosis type 1 (NF1). Several studies have previously described particularly severe forms of the disease in NF1 patients with deletion of the NF1 locus, but comprehensive descriptions of large cohorts are still missing to fully characterize this contiguous gene syndrome. NF1-deleted patients were enrolled and phenotypically characterized with a standardized questionnaire between 2005 and 2020 from a large French NF1 cohort. Statistical analyses for main NF1-associated symptoms were performed versus an NF1 reference population. A deletion of the NF1 gene was detected in 4% (139/3479) of molecularly confirmed NF1 index cases. The median age of the group at clinical investigations was 21 years old. A comprehensive clinical assessment showed that 93% (116/126) of NF1-deleted patients fulfilled the NIH criteria for NF1. More than half had café-au-lait spots, skinfold freckling, Lisch nodules, neurofibromas, neurological abnormalities, and cognitive impairment or learning disabilities. Comparison with previously described “classic” NF1 cohorts showed a significantly higher proportion of symptomatic spinal neurofibromas, dysmorphism, learning disabilities, malignancies, and skeletal and cardiovascular abnormalities in the NF1-deleted group. We described the largest NF1-deleted cohort to date and clarified the more severe phenotype observed in these patients. Full article

Neurofibromatosis (NF) is a neurocutaneous syndrome characterized by the development of tumors of the central or peripheral nervous system including the brain, spinal cord, organs, skin, and bones. There are three types of NF: NF1 accounting for 96% of all cases, NF2 in 3%, and schwannomatosis (SWN) in <1%. The NF1 gene is located on chromosome 17q11.2, which encodes for a tumor suppressor protein, neurofibromin, that functions as a negative regulator of Ras/MAPK and PI3K/mTOR signaling pathways. The NF2 gene is identified on chromosome 22q12, which encodes for merlin, a tumor suppressor protein related to ezrin-radixin-moesin that modulates the activity of PI3K/AKT, Raf/MEK/ERK, and mTOR signaling pathways. In contrast, molecular insights on the different forms of SWN remain unclear. Inactivating mutations in the tumor suppressor genes SMARCB1 and LZTR1 are considered responsible for a majority of cases. Recently, treatment strategies to target specific genetic or molecular events involved in their tumorigenesis are developed. This study discusses molecular pathways and related targeted therapies for NF1, NF2, and SWN and reviews recent clinical trials which involve NF patients. Full article

Childhood tumors of the central nervous system (CNS) and other entities affecting the spine are rare. Treatment options vary from surgical biopsy to partial, subtotal, and total resection, to radiation, to chemotherapy. The aim of this study is to investigate spinal deformity and subsequent surgical interventions in this patient cohort. A retrospective review at our institution identified children with CNS tumors, spinal tumors, and juxta-spinal tumors, as well as spinal deformities. Tumor entity, treatment, mobilization, and radiographic images were analyzed relative to the spinal deformity, using curve angles in two planes. Conservative or surgical interventions such as orthotic braces, growth-friendly spinal implants, and spinal fusions were evaluated and analyzed with respect to treatment results. Tumor entities in the 76 patients of this study included CNS tumors (n = 41), neurofibromatosis with spinal or paraspinal tumors (n = 14), bone tumors (n = 12), embryonal tumors (n = 7), and others (n = 2). The initial treatment consisted of surgical biopsy (n = 5), partial, subtotal, or total surgical resection (n = 59), or none (n = 12), followed by chemotherapy, radiotherapy, or both (n = 40). Out of 65 evaluated patients, 25 revealed a moderate or severe scoliotic deformity of 71° (range 21–116°), pathological thoracic kyphosis of 66° (range 50–130°), and lordosis of 61° (range 41–97°). Surgical treatment was performed on 21 patients with implantation of growth-friendly spinal implants (n = 9) as well as twelve dorsal spinal fusions (two with prior halo distraction). Surgical interventions significantly improved spinal deformities without additional neurological impairment. With the increasing number of children surviving rare tumors, attention should be focused on long-term problems such as spinal deformities and consequent disabilities. A significant number of children with CNS tumors, spinal tumors or juxta-spinal tumors required surgical intervention. Early information about spinal deformities and a close follow-up are mandatory for this patient group. Full article

Neurofibromatosis type 1 (NF-1) is a common hereditary neuro-cutaneous disease, with known gene mutations, that mainly involves the skin and nervous system. Multiple sclerosis (MS) is an acquired inflammatory disease in which the myelin of nerve cells in the brain and spinal cord is damaged. These two disease do not share any apparent pathological similarities. We herein present a 32-year-old woman with definite NF-1, who has recently been diagnosed with MS, which to the best of our knowledge is a rare co-occurrence. Though there are often neurologic sign and symptoms in patients with NF-1, they should not always be considered as the natural history of the disease, and other overlapped pathologies should be kept in mind, in order to not miss or postpone the efficient treatment. Full article