Home About us Contact
|
Home About us Contact | ||
|
|
||
Nerve Sheath Tumor (nerve + sheath_tumor)
Kinds of Nerve Sheath Tumor Selected AbstractsCutaneous Congenital Plexiform Cellular Schwannoma: A Simulant of Malignant Peripheral Nerve Sheath Tumor of Childhood , A Case Report and Literature ReviewJOURNAL OF CUTANEOUS PATHOLOGY, Issue 1 2005M. Matthews Cutaneous plexiform schwannoma is a rare multilobulated variant of benign schwannoma. When presenting as the cellular subtype with significantly increased proliferative rate, diagnostic consideration of a malignant peripheral nerve sheath tumor is prompted. However, follow up demonstrates a benign natural history with propensity for local recurrence and typical lack of association with neurocutaneous syndromes. These lesions most commonly occur as cutaneous and subcutaneous masses of the extremities in the first four decades. Only 9 cases of congenital tumors are reported. A case of congenital plexiform cellular schwannoma, presenting as a cutaneous mass measuring 3.5 × 2.5 × 2.0 cm, excised from the left upper arm of a 16 month old female is discussed. Regions of increased cellularity and proliferation co-localized and were unassociated with nuclear anaplasia. Mitotic figures numbered 7 per 10 400x fields. The tumor cells were strongly immunoreactive for S-100 protein. The MIB-1index was multifocally 25% and p53 protein over expression was present in 50% of nuclei. Following excision with free margins the tumor locally recurred after 16 months. The recurrence was morphologically identical to the original lesion. Recognition of the clinical and morphological characteristics of this rarely encountered benign neoplasm will facilitate in diagnosing this entity. [source] Fine-needle aspiration biopsy of metastatic malignant melanoma resembling a malignant peripheral nerve sheath tumorDIAGNOSTIC CYTOPATHOLOGY, Issue 10 2008Svetoslav Bardarov M.D. Abstract We report a case of metastatic malignant melanoma resembling a malignant peripheral sheath tumor, which posed a significant diagnostic challenge. The patient is a 76-year-old male, who presented in the emergency room with bilateral chest pain exacerbated by inspiration. The pain was present for 3 week and was not exacerbated by physical exercise. The diagnostic workup revealed bilateral parenchymal pulmonary infiltrates. The CT-scan guided fine-needle aspiration and the core biopsies of the largest pulmonary lesion revealed high-grade spindle cell neoplasm with individual cell apoptosis and necrosis. The immunohistochemical profile on the cell block showed that the cells are positive for Vimentin. The S-100 stain showed only focal positivity. The immunohistochemical stains for HMB45, Melan A, pancytokeratin, and smooth muscle actin were negative. Five years ago the patient was diagnosed with melanoma on the back with Clark level of IV. The melanoma was excised with clear margins and sentinel lymph nodes were negative. Careful examination of patient's previous slides revealed an area of spindle cell melanoma adjacent to a nodular type melanoma. Based on the patient's previous history, current clinico-pathologic presentation and immunohistochemical profile, the diagnosis of metastatic malignant melanoma resembling peripheral nerve sheath tumor was favored over the diagnosis of metastatic malignant spindle cell neoplasm of unknown primary site, which by itself is very rare clinical scenario. Diagn. Cytopathol. 2008;36:754,757. © 2008 Wiley-Liss, Inc. [source] Cytohistologic correlations in schwannomas (neurilemmomas), including "ancient," cellular, and epithelioid variantsDIAGNOSTIC CYTOPATHOLOGY, Issue 8 2006Jerzy Klijanienko M.D. Abstract Schwannoma accounts for one of the most common benign mesenchymal neoplasms of soft tissues. Although it is well defined in the cytology literature, particular histologic subtypes such as "ancient," cellular and epitheliod variants could be a source of diagnostic difficulties. We have reviewed cytology aspirates and corresponding histologic sections from 34 schwannomas diagnosed at Institut Curie. Histologically, 24 cases were classic, 5 were "ancient," 4 were cellular, and 1 was epithelioid schwannomas. No example of melanotic schwannoma was recorded. Original cytologic diagnosis was schwannoma in 13 (38.2%) cases, benign soft tissue tumor in 11 (32.4%), pleomorphic adenoma in 2 (6%) cases, angioma in 1 (2.9%) case, nodular fasciitis in 1 (2.9%) case, suspicious in 3 (8.8%) cases, and not satisfactory in 3 (8.8%) cases. There were no major differences between classical, "ancient," cellular, and epithelioid variants on cytology smears. Myxoid stroma, mast cells, and intranuclear inclusions were limited to classical subtype. Similarly, cyto-nuclear atypia was more frequent in classical subtype than in other subtypes. Schwannoma should be differentiated from well-differentiated malignant peripheral nerve sheath tumor, neurofibroma, and pleomorphic adenoma, in the last instance particularly for head and neck lesions. Diagn. Cytopathol. 2006;34:517,522. © 2006 Wiley-Liss, Inc. [source] Constitutive activation of the neuregulin-1/ErbB receptor signaling pathway is essential for the proliferation of a neoplastic Schwann cell lineGLIA, Issue 2 2003Paul W. Frohnert Abstract Neuregulin-1 (NRG-1) proteins promote Schwann cell survival, differentiation and proliferation during development. High levels of an NRG-like activity are also present in some human peripheral nerve sheath tumors, suggesting that NRG-1 isoforms may be involved in the development of these neoplasms. We examined the expression of NRG-1 and its receptors, the erbB membrane tyrosine kinases, in JS1 cells, a rapidly proliferating line derived from a chemically induced rat malignant peripheral nerve sheath tumor (MPNST). Relative to nontransformed Schwann cells, JS1 cells overexpress the NRG-1 receptor erbB3 and its erbB2 coreceptor; JS1 erbB2 transcripts show no evidence of the activating mutation commonly found in N-ethyl-N-nitrosourea-induced neoplasms. JS1 cells do not express the epidermal growth factor receptor (EGFR), a kinase implicated in the pathogenesis of a major subset of MPNSTs. JS1 cells also express mRNAs encoding multiple , and , isoforms from the glial growth factor and sensory and motor neuron-derived factor NRG-1 subfamilies. Stimulation with NRG-1, in the presence of forskolin produces a dose-dependent increase in JS1 DNA synthesis. Even in unstimulated JS1 cells, however, erbB2 and erbB3 are constitutively tyrosine phosphorylated. Reducing this constitutive phosphorylation with the specific erbB inhibitor PD158780 markedly impairs JS1 DNA synthesis. These observations support the hypothesis that NRG-1 isoforms and erbB kinases act in an autocrine and/or paracrine fashion to promote mitogenesis in JS1 cells. The absence of EGFR expression in JS1 cells suggests that constitutive activation of the NRG-1/erbB signaling pathway is an alternative means of inducing Schwann cell neoplasia. © 2003 Wiley-Liss, Inc. [source] Prognostic factors for the malignant triton tumor of the head and neckHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 5 2009Andrej Terzic MD Abstract Background. Malignant triton tumors are rare neoplasias consisting of a malignant peripheral nerve sheath tumor with additional rhabdomyoblastic differentiation. These tumors are highly aggressive and prognosis is poor. Our aim is to describe the outcome and to identify potential prognostic factors. Methods. From 1993 to 2005, 7 patients with a malignant triton tumor of the head and neck were treated at our institution. A literature search revealed another 46 published cases. All these cases were analyzed for outcome and prognostic factors. Results. Patients with primary tumors involving the nose and paranasal sinuses have better, patients involving the neck a poor prognosis. All other locations show an intermediate course. Complete surgical removal is of crucial importance. Additional radiation or chemotherapy show little effect. Conclusion. Location of the primary tumor is a key factor for prognosis. Complete surgical removal is the only treatment associated with survival.© 2009 Wiley Periodicals, Inc. Head Neck, 2009 [source] Fibrolamellar nerve sheath tumor or sclerotic neurofibroma?JOURNAL OF CUTANEOUS PATHOLOGY, Issue 11 2006Boncheol Goo MD [source] Cutaneous Congenital Plexiform Cellular Schwannoma: A Simulant of Malignant Peripheral Nerve Sheath Tumor of Childhood , A Case Report and Literature ReviewJOURNAL OF CUTANEOUS PATHOLOGY, Issue 1 2005M. Matthews Cutaneous plexiform schwannoma is a rare multilobulated variant of benign schwannoma. When presenting as the cellular subtype with significantly increased proliferative rate, diagnostic consideration of a malignant peripheral nerve sheath tumor is prompted. However, follow up demonstrates a benign natural history with propensity for local recurrence and typical lack of association with neurocutaneous syndromes. These lesions most commonly occur as cutaneous and subcutaneous masses of the extremities in the first four decades. Only 9 cases of congenital tumors are reported. A case of congenital plexiform cellular schwannoma, presenting as a cutaneous mass measuring 3.5 × 2.5 × 2.0 cm, excised from the left upper arm of a 16 month old female is discussed. Regions of increased cellularity and proliferation co-localized and were unassociated with nuclear anaplasia. Mitotic figures numbered 7 per 10 400x fields. The tumor cells were strongly immunoreactive for S-100 protein. The MIB-1index was multifocally 25% and p53 protein over expression was present in 50% of nuclei. Following excision with free margins the tumor locally recurred after 16 months. The recurrence was morphologically identical to the original lesion. Recognition of the clinical and morphological characteristics of this rarely encountered benign neoplasm will facilitate in diagnosing this entity. [source] Expression of PGP 9.5 in granular cell nerve sheath tumors: an immunohistochemical study of six casesJOURNAL OF CUTANEOUS PATHOLOGY, Issue 6 2001Meera Mahalingam Background: Protein gene product 9.5 (PGP 9.5) is expressed in brain at 20 to 50 times the levels detected in other organs. Immunohistochemical studies reveal this protein is localized to both central and peripheral neurons. Recently, PGP 9.5 is reported to be a useful marker for cellular neurothekeomas. Herein we test whether PGP 9.5 is a new marker for granular cell nerve sheath tumors. Material and Methods: An immunohistochemical analysis for PGP 9.5 expression was carried out on all cases with the diagnosis of granular cell nerve sheath tumor seen over a 2-year period. In addition, we compared expression of PGP 9.5 with other accepted markers for neuroectodermal tumors including anti-S-100 protein and NKI/C3 monoclonal antibodies. Results: Six granular cell nerve sheath tumors were diagnosed in over 80,000 dermatopathology specimens in the two-year period. These cases were all positive for PGP 9.5 as well as for S-100 protein and NK1/C3. Conclusion: These findings identify PGP 9.5 as a new immunohistochemical marker for use in the diagnosis of granular cell tumors. They also strengthen the histogenetic relationship between granular cell nerve sheath tumors and tumors of Schwann cell or perineurial origin. [source] Malignant peripheral nerve sheath tumor of the uterine cervix expressing both S-100 protein and HMB-45JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 6 2009Na Rae Kim Abstract A 50-year-old woman presented with a large cervical polypoid mass. Grossly, the mass occupied a substantial proportion of the cervical canal, measuring 6 cm. Histologically, the mass showed a spindle cell malignancy arranged in large fascicles that penetrated deeply into the fibromuscular wall of the cervix. The spindle cells were immunoreactive for both S-100 protein and HMB-45 antigen, but were negative for Melan-A. Electron microscopy showed that cytoplasmic processes of the spindle to oval tumor cells contained microtubules and were lined by basal lamina and abundant intercellular collagen spacing with no melanosomes in any stage. As far as we are aware, this is the ninth reported case of cervical malignant peripheral nerve sheath tumor (MPNST), and the second reported case of MPNST expressing HMB-45 antigen. [source] Pathology of soft-tissue tumors: Daily diagnosis, molecular cytogenetics and experimental approachPATHOLOGY INTERNATIONAL, Issue 8 2009Hiroshi Iwasaki This article reviews problems in diagnostic pathology and molecular cytogenetics of soft-tissue tumors. Also discussed are the origin of soft-tissue sarcomas and the molecular basis of effective target therapy for sarcomas. Molecular cytogenetic analysis of tumor-specific chromosomal translocations and associated fusion gene transcripts offers a useful adjunct to the diagnosis of soft-tissue tumors, but recent studies have indicated a growing number of fusion gene variations in each tumor type. In pleomorphic sarcoma/malignant fibrous histiocytoma, the alternative lengthening of telomeres (ALT) mechanism may result in formation of anaphase bridges and marked nuclear pleomorphism. The histogenesis of soft-tissue sarcomas has been a matter of controversy. In the present experimental model using s.c. injection of 3-methylcholanthrene in C57BL/6 mice pretreated with bone marrow-transplantation from green fluorescent protein (GFP)-positive green mice, the bone marrow-derived mesenchymal stem cells as well as the tissue-resident mesenchymal cells in the peripheral soft tissues are possible originators of sarcomagenesis. Little is known about a molecular basis of target therapy for sarcomas. Platelet-derived growth factor-BB (PDGF-BB) enhances the invasive activity of malignant peripheral nerve sheath tumor (MPNST) cells through platelet-derived growth factor receptor (PDGFR) phosphorylation, whereas imatinib mesylate inhibited such activity, suggesting that targeting PDGFR-, may result in the establishment of novel treatment for MPNST. In addition, emmprin is a transmembrane glycoprotein on tumor cells that stimulates peritumoral fibroblasts to produce matrix metalloproteinases (MMP), playing a crucial role in tumor progression, invasion and metastasis. The MMP upregulation mechanism mediated by tumor-associated emmprin may be a potentially useful target in anti-tumor invasion therapy for sarcomas. [source] Nestin expression as a new marker in malignant peripheral nerve sheath tumorsPATHOLOGY INTERNATIONAL, Issue 2 2007Satoko Shimada Malignant peripheral nerve sheath tumor (MPNST) can be difficult to diagnose because it lacks specific immunohistochemical markers. S-100, which is a useful marker of MPNST, has limited diagnostic utility. Recent studies suggest that nestin, which is an intermediate filament protein, is expressed in neuroectodermal stem cells. The diagnostic utility of immunostains for nestin and three other neural markers (S-100, CD56 and protein gene product 9.5 (PGP 9.5)) were evaluated in 35 cases of MPNST and in other spindle cell tumors. All MPNST cases were strongly positive for nestin and had cytoplasmic staining. Stains for S-100, CD56, and PGP 9.5 were positive in fewer cases (17/35, 11/35, and 29/35 cases, respectively), and had less extensive staining. Nestin was negative in 10/10 leiomyomas, and weak nestin expression was seen in 10/10 schwannomas, 3/10 neurofibromas, 2/8 synovial sarcomas, 2/10 liposarcomas, 4/7 carcinosarcomas and 3/7 malignant fibrous histiocytomas. In contrast, strong nestin positivity was seen in 10/10 rhabdomyosarcomas, 15/19 leiomyosarcomas, and 9/9 desmoplastic melanomas. Nestin is more sensitive for MPNST than other neural markers and immunostains for nestin in combination with other markers could be useful in the diagnosis of MPNST. [source] Malignant peripheral nerve sheath tumor arising in benign ancient schwannoma: A case report with an immunohistochemical studyPATHOLOGY INTERNATIONAL, Issue 2 2000Yoshiki Mikami A rare example of malignant transformation in an ancient schwannoma arisng in the right side of the neck of a 51-year-old man without any clinical manifestations suggesting neurofibromatosis is described. The tumor, approximately 4 cm at its largest dimension, was well circumscribed and had a direct connection with the sympathetic nerve. Microscopically, the central portion of the tumor showed features of ancient schwannoma characterized by extensive hyalinization with cystic degeneration, scattered spindle cells with hyperchromatic and tapered nuclei, and some symplastic changes. However, predominantly in the outer portion, a proliferation of spindle-shaped cells with enlarged nuclei was present. The nuclei of these cells showed irregular contours, coarse granular chromatin texture, and conspicuous nucleoli. Mitotic figures and small necrotic foci with scattered apoptotic bodies were also seen. Immunohistochemically, S-100 protein was almost negative in areas consisting of overtly atypical cells where the mitotic index evaluated with MIB-1 antibody was 30.5%. In contrast, S-100-positive bland spindle cells were scattered in an extensively hyalinized area with a labeling index less than 3%. P53 protein was strongly positive in atypical spindle cells. Although it is a very uncommon event, definite nuclear atypia, frequent mitotic figures, and the existence of small necrotic foci should be recognized as indicating a diagnosis of malignant degeneration of benign schwannoma. Immunohistochemistry would be useful as an ancillary technique in such a setting. [source] Expression of the zebrafish CD133/prominin1 genes in cellular proliferation zones in the embryonic central nervous system and sensory organsDEVELOPMENTAL DYNAMICS, Issue 6 2010Maura McGrail Abstract The CD133/prominin1 gene encodes a pentamembrane glycoprotein cell surface marker that is expressed in stem cells from neuroepithelial, hematopoietic, and various organ tissues. Here we report the analysis of two zebrafish CD133/prominin1 orthologues, prominin1a and prominin1b. The expression patterns of the zebrafish prominin1a and b genes were analyzed during embryogenesis using whole mount in situ hybridization. prominin1a and b show novel complementary and overlapping patterns of expression in proliferating zones in the developing sensory organs and central nervous system. The expression patterns suggest functional conservation of the zebrafish prominin1 genes. Initial analyses of prominin1a and b in neoplastic tissue show increased expression of both genes in a subpopulation of cells in malignant peripheral nerve sheath tumors in tp53 mutants. Based on these analyses, the zebrafish prominin1 genes will be useful markers for examining proliferating cell populations in adult organs, tissues, and tumors. Developmental Dynamics 239:1849,1857, 2010. © 2010 Wiley-Liss, Inc. [source] Cytologic spectrum of 227 fine-needle aspiration cases of chest-wall lesionsDIAGNOSTIC CYTOPATHOLOGY, Issue 6 2001Amit Goel M.D., D.N.B. Abstract This study was carried out with the objective of studying the cytomorphology of the wide variety of chest-wall lesions. Two hundred twenty-seven chest-wall lesions were studied over a period of 4 yr. Routine May-Grünwald-Giemsa (MGG) and hematoxylin-eosin (H&E) slides were studied along with special stains, whenever required. The malignant lesions comprised 36.13% of all cases (81/227). Of the 126 benign lesions, the majority were inflammatory in nature (68/126), the next commonest lesion being lipoma (38/126). Rare cases of tuberculosis involving the sternum, epithelioid leiomyosarcoma, and neuroendocrine tumors involving ribs, malignant nerve sheath tumors involving the chest wall, metastatic carcinoma of the stomach and prostate, and papillary carcinoma thyroid are reported in this series. Histopathology was available in 24 cases, and hematological correlation in one case. A 100% cytohistological and cytohematological correlation was found, with no false positives or false negatives. In conclusion, fine-needle aspiration cytology is a rapid, diagnostic tool, eliciting many interesting lesions in the chest wall. It is useful not only in detecting primary and metastatic lesions, but also in follow-up of tumor recurrence. Diagn. Cytopathol. 24:384,388, 2001. © 2001 Wiley-Liss, Inc. [source] How does the Schwann cell lineage form tumors in NF1?GLIA, Issue 14 2008Steven L. Carroll Abstract Neurofibromas are benign tumors of peripheral nerve that occur sporadically or in patients with the autosomal dominant tumor predisposition syndrome neurofibromatosis type 1 (NF1). Multiple neurofibroma subtypes exist which differ in their site of occurrence, their association with NF1, and their tendency to undergo transformation to become malignant peripheral nerve sheath tumors (MPNSTs), the most common malignancy associated with NF1. Most NF1 patients carry a constitutional mutation of the NF1 tumor suppressor gene. Neurofibromas develop in these patients when an unknown cell type in the Schwann cell lineage loses its remaining functional NF1 gene and initiates a complex series of interactions with other cell types; these interactions may be influenced by aberrant expression of growth factors and growth factor receptors and the action of modifier genes. Cells within certain neurofibroma subtypes subsequently accumulate additional mutations affecting the p19ARF -MDM2-TP53 and p16INK4A-Rb signaling cascades, mutations of other as yet unidentified genes, and amplification of growth factor receptor genes, resulting in their transformation into MPNSTs. These observations have been validated using a variety of transgenic and knockout mouse models that recapitulate neurofibroma and MPNST pathogenesis. A new generation of mouse models is also providing important new insights into the identity of the cell type in the Schwann cell lineage that gives rise to neurofibromas. Our improving understanding of the mechanisms underlying the pathogenesis of neurofibromas and MPNSTs raises intriguing new questions about the origin and pathogenesis of these neoplasms and establishes models for the development of new therapies targeting these neoplasms. © 2008 Wiley-Liss, Inc. [source] Constitutive activation of the neuregulin-1/ErbB receptor signaling pathway is essential for the proliferation of a neoplastic Schwann cell lineGLIA, Issue 2 2003Paul W. Frohnert Abstract Neuregulin-1 (NRG-1) proteins promote Schwann cell survival, differentiation and proliferation during development. High levels of an NRG-like activity are also present in some human peripheral nerve sheath tumors, suggesting that NRG-1 isoforms may be involved in the development of these neoplasms. We examined the expression of NRG-1 and its receptors, the erbB membrane tyrosine kinases, in JS1 cells, a rapidly proliferating line derived from a chemically induced rat malignant peripheral nerve sheath tumor (MPNST). Relative to nontransformed Schwann cells, JS1 cells overexpress the NRG-1 receptor erbB3 and its erbB2 coreceptor; JS1 erbB2 transcripts show no evidence of the activating mutation commonly found in N-ethyl-N-nitrosourea-induced neoplasms. JS1 cells do not express the epidermal growth factor receptor (EGFR), a kinase implicated in the pathogenesis of a major subset of MPNSTs. JS1 cells also express mRNAs encoding multiple , and , isoforms from the glial growth factor and sensory and motor neuron-derived factor NRG-1 subfamilies. Stimulation with NRG-1, in the presence of forskolin produces a dose-dependent increase in JS1 DNA synthesis. Even in unstimulated JS1 cells, however, erbB2 and erbB3 are constitutively tyrosine phosphorylated. Reducing this constitutive phosphorylation with the specific erbB inhibitor PD158780 markedly impairs JS1 DNA synthesis. These observations support the hypothesis that NRG-1 isoforms and erbB kinases act in an autocrine and/or paracrine fashion to promote mitogenesis in JS1 cells. The absence of EGFR expression in JS1 cells suggests that constitutive activation of the NRG-1/erbB signaling pathway is an alternative means of inducing Schwann cell neoplasia. © 2003 Wiley-Liss, Inc. [source] Malignant peripheral nerve sheath tumors of the head and neck: Management of 10 cases and literature review,HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 5 2007Amir Minovi MD Abstract Background. This study analyzes the management and outcomes of a series of 10 malignant peripheral nerve sheath tumors (MPNST) of the head and neck. Methods. From 1984 to 2004, 10 patients underwent surgical treatment of a MPNST. We retrospectively reviewed presenting symptoms, radiological findings, surgical management, and follow-up status and performed a literature review. Results. Eight tumors were located at the lateral skull base; 2 involved the vagus nerve in isolation. Two lesions were growing within the sinonasal tract. The most common presenting symptom was a rapidly enlarging cervical mass. Seventy percent of the tumors could be resected completely. Long-term follow-up showed a 2-year disease-specific survival rate of 50% and 5-year survival rate of 20%. Negative prognostic indicators were advanced tumor stage, early recurrence, and presumably also the presence of von Recklinghausen's disease. Postoperative adjuvant radiotherapy was found to make no difference in outcome. Conclusions. Although rare, MPNST is one of the most aggressive tumors in the head and neck area. Complete tumor removal is the mainstay of treatment and most important prognostic factor of MPNST. Adjuvant radiotherapy should be used to assist surgical excision in local control. The role of adjuvant chemotherapy remains controversial. © 2006 Wiley Periodicals, Inc. Head Neck, 2007. [source] Constitutional NF1 mutations in neurofibromatosis 1 patients with malignant peripheral nerve sheath tumors,,HUMAN MUTATION, Issue 5 2003Lan Kluwe Abstract Neurofibromatosis type 1 (NF1) patients have 10% of lifetime risk for developing malignant peripheral nerve sheath tumors (MPNST), one of the most aggressive cancers. We examined the spectrum of constitutional NF1 mutations among 24 NF1 patients with MPNST. We found mutations in 18 patients: four megabase deletions involving the NF1 gene, 13 truncating mutations, and only one missense mutation. One deletion included both exonic and intronic sequences. No typical splicing mutation was found. Five of these mutations were novel: c.3686delA, c.197_204+9del17, c.3044T>C (p.Leu1015Pro), c.2497delT, and c.6020_6027dup. The proportion of megabase deletions of the NF1 gene found in patients with MPNST (17%=4/24) was higher than that in a group of unselected NF1 patients (5.4%=27/500). © 2003 Wiley-Liss, Inc. [source] Recent developments in benign peripheral nerve sheath tumorsJOURNAL OF CUTANEOUS PATHOLOGY, Issue 12 2008Dan C. Phan MD [source] Expression of PGP 9.5 in granular cell nerve sheath tumors: an immunohistochemical study of six casesJOURNAL OF CUTANEOUS PATHOLOGY, Issue 6 2001Meera Mahalingam Background: Protein gene product 9.5 (PGP 9.5) is expressed in brain at 20 to 50 times the levels detected in other organs. Immunohistochemical studies reveal this protein is localized to both central and peripheral neurons. Recently, PGP 9.5 is reported to be a useful marker for cellular neurothekeomas. Herein we test whether PGP 9.5 is a new marker for granular cell nerve sheath tumors. Material and Methods: An immunohistochemical analysis for PGP 9.5 expression was carried out on all cases with the diagnosis of granular cell nerve sheath tumor seen over a 2-year period. In addition, we compared expression of PGP 9.5 with other accepted markers for neuroectodermal tumors including anti-S-100 protein and NKI/C3 monoclonal antibodies. Results: Six granular cell nerve sheath tumors were diagnosed in over 80,000 dermatopathology specimens in the two-year period. These cases were all positive for PGP 9.5 as well as for S-100 protein and NK1/C3. Conclusion: These findings identify PGP 9.5 as a new immunohistochemical marker for use in the diagnosis of granular cell tumors. They also strengthen the histogenetic relationship between granular cell nerve sheath tumors and tumors of Schwann cell or perineurial origin. [source] In vitro studies of steroid hormones in neurofibromatosis 1 tumors and schwann cellsMOLECULAR CARCINOGENESIS, Issue 7 2007Lauren Fishbein Abstract The most common NF1 feature is the benign neurofibroma, which consists predominantly of Schwann cells. Dermal neurofibromas usually arise during puberty and increase in number throughout adulthood. Plexiform neurofibromas, associated with larger nerves, are often congenital and can be life threatening. Malignant peripheral nerve sheath tumors (MPNST) in NF1 are believed to arise from plexiforms in 5%,10% of patients. There are reports of increased potential for malignant transformation of plexiform tumors and increase in dermal neurofibromas, during pregnancy. These observations suggest that steroid hormones influence neurofibroma growth, and our work is the first to examine steroid hormone receptor expression and ligand-mediated cell growth and survival in normal human Schwann cells and neurofibroma-derived Schwann cell cultures. Immunohistochemistry and real-time PCR showed that estrogen receptors (ERs), progesterone receptor (PR), and androgen receptor are differentially expressed in primary neurofibromas and in NF1 tumor-derived Schwann cell cultures compared to normal Schwann cells. However, there is substantial heterogeneity, with no clear divisions based on tumor type or gender. The in vitro effects of steroid hormone receptor ligands on proliferation and apoptosis of early passage NF1 tumor-derived Schwann cell cultures were compared to normal Schwann cell cultures. Some statistically significant changes in proliferation and apoptosis were found, also showing heterogeneity across groups and ligands. Overall, the changes are consistent with increased cell accumulation. Our data suggest that steroid hormones can directly influence neurofibroma initiation or progression by acting through their cognate receptor, but that these effects may only apply to a subset of tumors, in either gender. © 2007 Wiley-Liss, Inc. [source] Nestin expression as a new marker in malignant peripheral nerve sheath tumorsPATHOLOGY INTERNATIONAL, Issue 2 2007Satoko Shimada Malignant peripheral nerve sheath tumor (MPNST) can be difficult to diagnose because it lacks specific immunohistochemical markers. S-100, which is a useful marker of MPNST, has limited diagnostic utility. Recent studies suggest that nestin, which is an intermediate filament protein, is expressed in neuroectodermal stem cells. The diagnostic utility of immunostains for nestin and three other neural markers (S-100, CD56 and protein gene product 9.5 (PGP 9.5)) were evaluated in 35 cases of MPNST and in other spindle cell tumors. All MPNST cases were strongly positive for nestin and had cytoplasmic staining. Stains for S-100, CD56, and PGP 9.5 were positive in fewer cases (17/35, 11/35, and 29/35 cases, respectively), and had less extensive staining. Nestin was negative in 10/10 leiomyomas, and weak nestin expression was seen in 10/10 schwannomas, 3/10 neurofibromas, 2/8 synovial sarcomas, 2/10 liposarcomas, 4/7 carcinosarcomas and 3/7 malignant fibrous histiocytomas. In contrast, strong nestin positivity was seen in 10/10 rhabdomyosarcomas, 15/19 leiomyosarcomas, and 9/9 desmoplastic melanomas. Nestin is more sensitive for MPNST than other neural markers and immunostains for nestin in combination with other markers could be useful in the diagnosis of MPNST. [source] | |||||||||||||