scholarly journals Nerve sheath tumor surgery: case-guided discussion of ambiguous findings, appropriateness of removal, repeated surgery, and nerve repairs

2007 ◽  
Vol 22 (6) ◽  
pp. 1-9 ◽  
Author(s):  
Thomas Kretschmer ◽  
Gregor Antoniadis ◽  
Christian Heinen ◽  
Wolfgang Börm ◽  
Christian Scheller ◽  
...  

✓In this article the authors attempt to raise awareness of the pitfalls and controversial issues in nerve tumor surgery. In a case-guided format, examples of ambiguous findings, inappropriate tumor removal, repeated surgery, and nerve repairs are provided. The authors also discuss the need to establish a correct diagnosis preoperatively and to avoid the erroneous identification of malignant peripheral nerve sheath tumors (MPNSTs). They emphasize that not all of the principles of soft tissue sarcoma treatment protocols are applicable to MPNST. A situation of repeated surgery for supposedly malignant tumor is described, and an outline of the indications for, and an approach to, repair after lesion removal is given.

Author(s):  
Christian Heinen ◽  
Thomas Kretschmer

A benign peripheral nerve sheath tumor is illustrated in a case presentation of a painful mass in the medial thigh, with paresthesias radiating along the course of the saphenous nerve. The presenting features, appropriate workup, treatment timing, surgical strategies, follow-up, and results for nerve-associated masses are outlined. Specific imaging findings for peripheral nerve sheath tumors on contrast-enhanced MR imaging and the merits of high-resolution ultrasound are detailed. The typical features of a well-defined and noninvasive peripheral nerve tumor, the principles of exploration, and microsurgical enucleation technique are highlighted. Other nerve tumor entities that should be considered in the differential diagnosis, as well as their respective features, are discussed.


2019 ◽  
Vol 18 (1) ◽  
pp. 60-68 ◽  
Author(s):  
Jonathan J Stone ◽  
Robert J Spinner

Abstract BACKGROUND Intraneural dissection is a useful technique for achieving gross total resection and preserving functional fascicles for peripheral nerve tumors. Finding the correct tissue plane is the critical step for safe successful enucleation. The authors hypothesized that the yellow color of benign nerve tumors can be used to identify surgical planes. OBJECTIVE To describe a technique to find the correct intraneural dissection plane based on a quantified yellow appearance during resection of benign peripheral nerve sheath tumors. METHODS Intraoperative photographs were reviewed to determine the percentage of yellow that tumors appeared at different phases of surgery. A technique was developed to quantitatively measure the amount of yellow using Photoshop. Previously published journal articles containing color images of peripheral nerve tumor resections were also analyzed for yellow tumor color. RESULTS There were 24 patients with suitable images to permit measurement of color for 3 steps of the procedure. The average percentages of yellow for tumor exposure, tumor resection, and removed specimen were 36.5%, 59.1%, and 80.4%, respectively (P < .001). Three publications were found that contained high-quality images of at least 2 phases of the surgery with average yellow content of 47.4% and 84% (P < .01). CONCLUSION The simple observation that a benign nerve sheath tumor is yellow in color can be used to guide surgical resection and achieve excellent outcomes. Intraneural dissection through the pseudocapsule should be pursued layer by layer until a yellow true capsule is found. By sparing functional nervous tissue within the pseudocapsule, this technique may lead to improved neurological outcomes.


Neurosurgery ◽  
2009 ◽  
Vol 64 (suppl_2) ◽  
pp. A33-A43 ◽  
Author(s):  
Judith A. Murovic ◽  
Iris C. Gibbs ◽  
Steven D. Chang ◽  
Bret C. Mobley ◽  
Jon Park ◽  
...  

Abstract OBJECTIVE To conduct a retrospective review of outcomes in 15 patients with 18 foraminal tumors, including 17 benign peripheral nerve sheath tumors and 1 malignant peripheral nerve sheath tumor, who underwent CyberKnife (Accuray, Inc., Sunnyvale, CA) radiosurgery at Stanford University Medical Center from 1999 to 2006. METHODS Symptoms and findings, neurofibromatosis (NF) association, previous radiation, imaging, dosimetry, tumor volume, central necrosis, and the relation of these factors to outcomes were evaluated. RESULTS Before treatment, 1 asymptomatic patient had radiculopathic findings, 3 patients experienced local pain with intact neurological examinations, and 7 patients had radiculopathic complaints with intact (1 patient), radiculopathic (4 patients), or radiculomyelopathic examinations (2 patients). Five patients had myelopathic complaints and findings. Three patients had NF1-associated neurofibromas, 1 patient with NF2 had a schwannoma, and 1 patient had a schwannomatosis-related lesion. Two likely radiation-induced lesions, a neurofibroma and a malignant peripheral nerve sheath tumor, were observed. Prescribed doses ranging from 16 to 24 Gy, delivered in 1 to 3 fractions of 6 to 20 Gy, resulted in maximum tumor doses ranging from 20.9 to 30 Gy. Target volumes ranged from 1.36 to 16.9 mL. After radiosurgery, the asymptomatic case remained asymptomatic, and neurological findings improved. Thirteen of 15 symptomatic patients with (12 patients) or without (3 patients) neurological findings improved (3 cases after resection) or remained stable, and 2 patients worsened. Symptoms and examinations remained stable or improved in 8 (80%) of 10 patients with schwannomas and 3 (60%) of 5 patients with neurofibromas. Tumor volumes decreased in 12 (67%) of 18 tumors and increased in 3 tumors. Tumor volumes decreased in 8 of 10 schwannomas and 3 of 7 neurofibromas. Central necrosis developed in 8 (44%) of 18 tumors. CONCLUSION CyberKnife radiosurgery resulted in pain relief and functional preservation in selected foraminal peripheral nerve sheath tumors and a malignant peripheral nerve sheath tumor. Symptomatic and neurological improvements were more noticeable with schwannomas. Myelopathic symptoms may necessitate surgical debulking before radiosurgery.


2006 ◽  
Vol 130 (12) ◽  
pp. 1878-1881 ◽  
Author(s):  
Christopher J. Stasik ◽  
Ossama Tawfik

Abstract Malignant peripheral nerve sheath tumors arise from Schwann cells or within existing neurofibromas and have a strong association with type 1 neurofibromatosis. These tumors are histologically diverse and may contain malignant areas of divergent mesenchymal differentiation, the most common of which is skeletal muscle (rhabdomyosarcoma). Malignant peripheral nerve sheath tumor with rhabdomyosarcomatous differentiation is also known as malignant triton tumor. Malignant triton tumor has a worse prognosis than classic malignant peripheral nerve sheath tumor does, and the correct diagnosis requires attention to the clinical history and knowledge of the complexities regarding its differential diagnosis. In this review we discuss the clinical, histopathological, immunohistochemical, and prognostic features of this rare neoplasm.


2015 ◽  
Vol 35 (12) ◽  
pp. 965-974 ◽  
Author(s):  
Gisele S. Boos ◽  
Daniele M. Bassuino ◽  
Fabiana Wurster ◽  
Neusa B. Castro ◽  
Tatiane T.N. Watanabe ◽  
...  

Abstract: In this retrospective study was determined the frequency of canine skin peripheral nerve sheath tumors (PNST) in cases diagnosed by the Setor de Patologia Veterinária of the Universidade Federal do Rio Grande do Sul (SPV-UFRGS), Brazil, between the years 2000 and 2012. The canine profiles, as well as histological, immunohistochemical and prognostic aspects of the tumors were based on 70 samples, comprising 40 females, 29 males and one unspecified sample. Between 2000 and 2012, 2,984 skin tumors of dogs were diagnosed in the SPV-UFRGS, totaling 2.34% of skin neoplasms in dogs. Animals that comprised the largest amount of samples (43%) were those with no breed (SRD), followed by German Shepherds (10%). Females were more affected than males (40/70 - 57% and 29/70 - 41% respectively). Skin PNST of this research showed predominant localization on the limbs (40% in the forelimbs and 29% in the hindlimbs); affecting adult dogs, mostly aged between 8 and 11 years (54%). The samples were routinely processed for hematoxylin and eosin, and were also evaluated by toluidine blue and Masson's trichrome staining, and immunohistochemistry (IHC) anti-vimentin, -S-100, -GFAP, -actin, von Willebrand factor and neurofilament. Anisocytosis and anisokaryosis, mitotic index, intratumoral necrosis, invasion of adjacent tissues, tumor location, local recurrence and metastasis were related to the diagnosis of benign (49/70) or malignant tumor (21/70). The Antoni A histological pattern was observed more frequently in benign tumors. The immunohistochemistry helped to diagnose PNST, and anti-vimentin and anti-protein S-100 showed the highest rates of immunostaining. Throughout statistical analysis of animals with tumor recurrence, it was found that the chance of an animal with a malignant peripheral nerve sheath tumor to develop recurrence is 4.61 times higher than in an animal that had a benign tumor.


2014 ◽  
Vol 21 (3) ◽  
pp. 367-371 ◽  
Author(s):  
Yaxiong Li ◽  
Fengshi Fan ◽  
Jianguo Xu ◽  
Jie An ◽  
Weining Zhang

Primary malignant peripheral nerve sheath tumors (MPNSTs) are extremely rare in patients without a history of neurofibromatosis; only 18 cases have been reported in the English-language literature to this point. The authors report their experience with 1 new case of a primary MPNST. A 33-year-old woman presented with low-back pain radiating to the right calf that progressed over 1 year. Magnetic resonance imaging of the spine revealed an intradural extramedullary lesion at the T12–L1 level. The patient was diagnosed with primary MPNST, underwent two surgical excisions and radiation therapy, and developed leptomeningeal metastases as well as brain metastases. The patient revisited the emergency room with sudden loss of consciousness. A brain CT scan displayed bilateral lateral ventricle enlargement, for which a ventriculoperitoneal shunt was inserted. These symptoms have not been described in any previous report. Primary spinal MPNST is an exceedingly rare entity, and the overall prognosis is very poor. To the authors' knowledge, no standard of care for primary spinal MPNSTs has yet been established. All 19 cases of primary spinal MPNSTs are reviewed, and the authors discuss their clinical, radiological, and therapeutic features and outcomes.


Cells ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 972 ◽  
Author(s):  
Zachary J. Brandt ◽  
Paula N. North ◽  
Brian A. Link

The cellular signaling pathways underlying peripheral nerve sheath tumor (PNST) formation are poorly understood. Hippo signaling has been recently implicated in the biology of various cancers, and is thought to function downstream of mutations in the known PNST driver, NF2. Utilizing CRISPR-Cas9 gene editing, we targeted the canonical Hippo signaling kinase Lats2. We show that, while germline deletion leads to early lethality, targeted somatic mutations of zebrafish lats2 leads to peripheral nerve sheath tumor formation. These peripheral nerve sheath tumors exhibit high levels of Hippo effectors Yap and Taz, suggesting that dysregulation of these transcriptional co-factors drives PNST formation in this model. These data indicate that somatic lats2 deletion in zebrafish can serve as a powerful experimental platform to probe the mechanisms of PNST formation and progression.


2019 ◽  
Author(s):  
Keila E Torres ◽  
Wei-Lien Wang ◽  
Alexander Lazar ◽  
Ian E McCutcheon

Peripheral nerve sheath tumors represent a spectrum of entities ranging from benign tumors, such as schwannoma, to high-grade malignant tumors termed malignant peripheral nerve sheath tumors. In this chapter, we discuss current concepts and problematic areas in the diagnosis, treatment, and management of peripheral nerve sheath tumors. We discuss the major categories of nerve sheath tumors including schwannomas, neurofibromas, and malignant peripheral nerve sheath tumors. The different benign variants and their propensity for malignant transformation are highlighted. We suggest useful guidelines for the surgical management of these challenging cases. Finally, we discuss some of the advances in molecular biology that have provided new insights into the nature of the various peripheral nerve sheath tumors and suggest potential novel targeted therapeutic strategies for these tumors. This review contains 11 figures, 5 tables and 66 references. Key Words: malignant peripheral nerve sheath tumors, nerve sheath tumor, neurofibroma, neurofibromatosis, schwannoma, schwannomatosis, NF1, NF2


2018 ◽  
Author(s):  
Keila E Torres ◽  
Wei-Lien Wang ◽  
Alexander Lazar ◽  
Ian E McCutcheon

Peripheral nerve sheath tumors represent a spectrum of entities ranging from benign tumors, such as schwannoma, to high-grade malignant tumors termed malignant peripheral nerve sheath tumors. In this chapter, we discuss current concepts and problematic areas in the diagnosis, treatment, and management of peripheral nerve sheath tumors. We discuss the major categories of nerve sheath tumors including schwannomas, neurofibromas, and malignant peripheral nerve sheath tumors. The different benign variants and their propensity for malignant transformation are highlighted. We suggest useful guidelines for the surgical management of these challenging cases. Finally, we discuss some of the advances in molecular biology that have provided new insights into the nature of the various peripheral nerve sheath tumors and suggest potential novel targeted therapeutic strategies for these tumors. This review contains 11 figures, 5 tables and 66 references. Key Words: malignant peripheral nerve sheath tumors, nerve sheath tumor, neurofibroma, neurofibromatosis, schwannoma, schwannomatosis, NF1, NF2


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