scholarly journals Diagnostic Pathology of Tumors of Peripheral Nerve

Neurosurgery ◽  
2021 ◽  
Vol 88 (3) ◽  
pp. 443-456
Author(s):  
Sarra M Belakhoua ◽  
Fausto J Rodriguez

Abstract Neoplasms of the peripheral nervous system represent a heterogenous group with a wide spectrum of morphological features and biological potential. They range from benign and curable by complete excision (schwannoma and soft tissue perineurioma) to benign but potentially aggressive at the local level (plexiform neurofibroma) to the highly malignant (malignant peripheral nerve sheath tumors [MPNST]). In this review, we discuss the diagnostic and pathologic features of common peripheral nerve sheath tumors, particularly those that may be encountered in the intracranial compartment or in the spine and paraspinal region. The discussion will cover schwannoma, neurofibroma, atypical neurofibromatous neoplasms of uncertain biological potential, intraneural and soft tissue perineurioma, hybrid nerve sheath tumors, MPNST, and the recently renamed enigmatic tumor, malignant melanotic nerve sheath tumor, formerly referred to as melanotic schwannoma. We also discuss the diagnostic relevance of these neoplasms to specific genetic and familial syndromes of nerve, including neurofibromatosis 1, neurofibromatosis 2, and schwannomatosis. In addition, we discuss updates in our understanding of the molecular alterations that represent key drivers of these neoplasms, including neurofibromatosis type 1 and type 2, SMARCB1, LZTR1, and PRKAR1A loss, as well as the acquisition of CDKN2A/B mutations and alterations in the polycomb repressor complex members (SUZ12 and EED) in the malignant progression to MPNST. In summary, this review covers practical aspects of pathologic diagnosis with updates relevant to neurosurgical practice.

1999 ◽  
Vol 2 (4) ◽  
pp. 377-384 ◽  
Author(s):  
Helen Liapis ◽  
Edith F. Marley ◽  
Yuan Lin ◽  
Louis P. Dehner

Malignant peripheral nerve sheath tumors (MPNSTs) are uncommon soft tissue tumors. In children with neurofibromatosis 1 (NF1), a MPNST often arises in a preexisting neurofibroma, or may represent an initial manifestation without other obvious stigmata of the disease. The development of MPNSTs may be associated with instability of the p53 tumor suppressor gene since it is the most frequent genetic abnormality in soft tissue sarcomas. To assess the presence of p53 accumulation in MPNSTs and its correlation with clinical and pathologic features, we studied 12 neurofibromas (NFs), including 4 tumors with cellular features (one congenital) and 10 MPNSTs. Six MPNSTs were associated with NF1, all of which developed within a plexiform neurofibroma. Cell proliferation evaluated with an antibody to Ki-67 and nuclear p53 staining were both detected by immunohistochemistry We found p53 positivity in 60% of MPNSTs. All NFs except the congenital tumor were p53 immunonegative ( P < 0.01). Rare p53-positive nuclei were detected in the transitional zone in two of six MPNSTs arising in plexiform NFs. Ki-67 distinguished the NFs from MPNSTs ( P < 0.005). Half of the NF1 patients with p53-positive MPNSTs developed recurrence or metastases or developed a second malignancy within 2 years of diagnosis, whereas patients with p53-positive sporadic MPNSTs were free of disease 1 to 7 years later. We found p53 accumulation more frequently in NF1-associated MPNSTs. p53 mutations may be an additional biologic factor to account for the poor prognosis in these tumors.


2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi115-vi115
Author(s):  
Yoon Jae Choi ◽  
Mari Perez-Rosendahl

Abstract Hybrid nerve sheath tumors are new disease entity incorporated in WHO classification of tumors of the central nervous system 2016 version that includes benign peripheral nerve sheath tumors with combined features of more than one conventional type. Ronellenfitsch et al recently reported one case with ERBB2 D769Y mutation with good clinical response to lapatinib in 2020. We report two cases with imaging findings of multiple peripheral nerve sheath tumors with pathology proven hybrid nerve sheath tumors with ERBB2 mutations. Patient 1 has neurofibroma/schwannoma hybrid nerve sheath tumor with ERBB2 D769Y mutation and patient 2 has plexiform neurofibroma/schwannoma hybrid nerve sheath tumor with ERBB2 V777L mutation. Both of our patients have similar clinical features with adult-onset multiple peripheral nerve sheath tumors without other systemic features of neurofibromatosis type1 or vestibular schwannomas or family history. Hybrid nerve sheath tumors are newly recognized disease and more than half of the cases have multiple peripheral nerve sheath tumors, suggestive of tumor syndrome. Patients with multiple peripheral nerve sheath tumors without systemic features of neurofibromatosis type1 or vestibular schwannomas should be screened for genetic/molecular tests including ERBB2 mutation that might provide treatment options for these patients.


Author(s):  
Marie-Noëlle Hébert-Blouin

Malignant peripheral nerve sheath tumors (PNSTs) are soft tissue sarcomas arising from a peripheral nerve or a pre-existing benign nerve sheath tumor or are sarcomas with features of Schwann-cell differentiation. Differentiating between benign and malignant PNSTs can be challenging. The chapter begins with a case example and then discusses assessment, investigations (including imaging), and diagnosis of malignant PNSTs, as well as the steps involved in decision-making about management of a malignant PNST. The surgical principles and goals for resection of a malignant PNST, the adjuvant therapies used in treatment, and the complications and outcomes of treatment are presented.


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.


Genes ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 1024
Author(s):  
Angela C. Hirbe ◽  
Rebecca D. Dodd ◽  
Christine A. Pratilas

Nerve sheath tumors arising in the context of neurofibromatosis type 1 (NF1) include benign tumors such as cutaneous, diffuse and plexiform neurofibromas; atypical neurofibromas or atypical neurofibromatosis neoplasms of uncertain biological potential (ANNUBP); and the aggressive soft tissue sarcoma, the malignant peripheral nerve sheath tumor (MPNST) [...]


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.


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.


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.


Sarcoma ◽  
2014 ◽  
Vol 2014 ◽  
pp. 1-19 ◽  
Author(s):  
Faris Shweikeh ◽  
Laura Bukavina ◽  
Kashif Saeed ◽  
Reem Sarkis ◽  
Aarushi Suneja ◽  
...  

Bone and soft tissue malignancies account for a small portion of brain metastases. In this review, we characterize their incidence, treatments, and prognosis. Most of the data in the literature is based on case reports and small case series. Less than 5% of brain metastases are from bone and soft tissue sarcomas, occurring most commonly in Ewing’s sarcoma, malignant fibrous tumors, and osteosarcoma. Mean interval from initial cancer diagnosis to brain metastasis is in the range of 20–30 months, with most being detected before 24 months (osteosarcoma, Ewing sarcoma, chordoma, angiosarcoma, and rhabdomyosarcoma), some at 24–36 months (malignant fibrous tumors, malignant peripheral nerve sheath tumors, and alveolar soft part sarcoma), and a few after 36 months (chondrosarcoma and liposarcoma). Overall mean survival ranges between 7 and 16 months, with the majority surviving < 12 months (Ewing’s sarcoma, liposarcoma, malignant fibrous tumors, malignant peripheral nerve sheath tumors, angiosarcoma and chordomas). Management is heterogeneous involving surgery, radiosurgery, radiotherapy, and chemotherapy. While a survival advantage may exist for those given aggressive treatment involving surgical resection, such patients tended to have a favorable preoperative performance status and minimal systemic disease.


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