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Results for “Neuroectodermal Tumors”

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PubMed1985

Primitive neuroectodermal tumor: a newly recognized cause of early fetal death.

Reviews in the literature of fetal and neonatal neoplasms deal only with congenital tumors, that is, tumors presenting at or shortly after birth. Virtually nothing is known about neoplasms occurring in the embryonal period or early fetal life. We report five small macerated fetuses with a very primitive embryonal tumor of neuroectodermal origin. The tumor characteristically showed massive vascular permeation. Expulsion of the fetus occurred during the fourth or fifth month of pregnancy. It is suggested that this primitive neuroectodermal tumor is a "new" cause of spontaneous late abortion.

Blood Vessels↗

PubMed2001

Cytogenetic and histopathologic studies of congenital supratentorial primitive neuroectodermal tumors: a case report.

Primitive neuroectodermal tumors (PNET) represent about 25% of primary central nervous system tumors in childhood, but congenital PNETs are rare. Cytogenetic studies and studies on molecular pathology have identified several genetic alterations in medulloblastoma, but molecular investigations on supratentorial PNETs are infrequent. We present a male newborn with a large congenital PNET of the right cerebral hemisphere and the molecular analysis of the tumor. Tumor tissue was investigated by routine histology and immunohistochemistry. Fluorescence in-situ hybridization was carried out on native tumor tissue to investigate deletions on chromosome 17p and to analyze c-Myc or N-Myc amplifications. Histologic examination revealed a primitive neuroectodermal tumor with massive extension covering almost the entire right hemisphere. Genetic analysis of the native tumor tissue of our patient excluded a deletion of chromosome 17p. An amplification of the c-Myc or N-Myc oncogene was absent using fluorescence in-situ hybridization. Despite unremarkable genetic analysis in our case prognosis was poor, suggesting that there are additional, yet unknown constitutional genetic aberrations in the pathogenesis of congenital supratentorial PNET.

Biomarkers, Tumor↗

PubMed1996

Small round blue cell tumors in bone: prognostic factors correlated to Ewing's sarcoma and neuroectodermal tumors.

Ewing's sarcoma and peripheral neuroectodermal tumors are the most common small round blue cell tumors of bone. Accurate prognostic factors are required to define guidelines to standardize the treatment modalities and to adapt these modalities to the potential evolution of the disease. The various factors that have emerged in the literature as influences on the outcome of patients with Ewing's sarcoma or peripheral neuroectodermal tumors of bone are considered in this review. The presence of metastases at the clinical onset of the disease represents the most adverse prognostic factor. For nonmetastatic patients, axial location appears to be the most unfavorable factor, despite initial tumor volume, by showing that the tumor burden could be a more appropriate indicator of patient outcome. The importance of a local control of the disease by surgery has been emphasized, and the value of the histopathologic evaluation of the response to chemotherapy has been stressed.

Age Factors↗

PubMed2000

Mutations of the INI1 rhabdoid tumor suppressor gene in medulloblastomas and primitive neuroectodermal tumors of the central nervous system.

Germ-line and somatic mutations of the hSNF5/INI1 gene have been reported in atypical teratoid/rhabdoid tumors (AT/RTs) of the brain, consistent with its role as a tumor suppressor gene. In the present study, we determined the frequency of deletions and mutations of INI1 in 52 children whose original diagnosis was medulloblastoma (MB) or primitive neuroectodermal tumor (PNET) of the central nervous system. Mutations were detected in DNA isolated from four tumors, all from children less than 3 years of age at diagnosis. Two of the four were reviewed and reclassified as atypical teratoid tumor, whereas there was insufficient material to establish this diagnosis in the two remaining cases. The relatively low frequency of mutations, even in a large series of infants, suggests that loss of sequences from chromosome 22 and/or mutations of INI1 do not account for the poor prognosis of children with MB or PNET who are less than 3 years of age at diagnosis. Nevertheless, chromosome 22 deletion and INI1-mutation analysis of infants with MB/PNET should be considered for all children who are less than 1 year of age. Detection of these mutations suggests that the child has an AT/RT, rather than a MB/PNET, a finding with important prognostic value.

Adolescent↗

PubMed1995

Primitive neuroectodermal tumor of maxilla in an adult.

Primitive neuroectodermal tumor is primarily a central nervous system tumor. These tumors are generally manifest in infancy or early childhood. The following article reports a rare case of primitive neuroectodermal tumor in posterior maxilla in an adult. Treatment for primitive neuroectodermal tumor in extracranial sites in adults is not clearly defined in the literature. This case was treated by combined chemotherapy followed by radiotherapy, which failed to cause regression of the lesion.

Adult↗

PubMedDate not supplied

Malignant round cell tumor of bone with neural differentiation (neuroectodermal tumor).

A malignant round cell tumor primary in bone is reported in a young girl, showing histologically rosette formation and pseudoalveolar spaces. Vimentin, NSE, and S-100 were positive. Electron microscopy demonstrated abundant glycogen and neural features such as cell processes, microtubules, and occasional dense-core granules. Whether this neuroectodermal tumor represents a separate entity or is a variant of Ewing's sarcoma should wait for further experience, in the light of recent evidence suggesting that Ewing's sarcoma arises from primitive multipotential cells.

Adolescent↗

PubMed1999

Bone morphogenetic proteins-2 and -4 attenuate apoptosis in a cerebellar primitive neuroectodermal tumor cell line.

Similarities between primitive neuroectodermal tumors and central nervous system (CNS) progenitor cells have evoked interest in the response of these tumors to endogenous growth factors. The bone morphogenetic proteins (BMPs) have recently been found to regulate survival and differentiation of CNS progenitor cell populations. In this study, we investigated the effects of BMP-2, BMP-4, and BMP-6 on the undifferentiated cerebellar primitive neuroectodermal tumor or medulloblastoma cell line DAOY. Analysis by reverse transcriptase-polymerase chain reaction showed that mRNAs for type IA and type II BMP receptors were present in control cultures. In cultures treated with BMP-2, mRNAs for BMP receptor type IB and the activin R-I receptor became evident. Cultures were analyzed for total cell counts, proliferating cell nuclear antigen (PCNA), and apoptotic DNA fragmentation. There was a significant increase in total cell number in the BMP-2 and BMP-4 treatment groups, without any change in PCNA reactivity, and a dramatic decrease in the proportion of apoptotic nuclei at concentrations of BMP-2 and BMP-4 above 5 ng/ml (P<0.001). These effects were not observed with BMP-6, TGF-beta1 or GDNF. These results suggest that the increase in total cell number is due to the attenuation of apoptosis by BMP-2 and BMP-4. The anti-apoptotic effect of BMP-2 and BMP-4 on this neuroectodermal cell line has potential clinical implications for neuroectodermal tumors.

Apoptosis↗

PubMed1995

Animal models of medulloblastomas and related primitive neuroectodermal tumors. A review.

Primitive neuroectodermal tumors (PNET) belong to a family of pediatric neoplasms of the central nervous system (CNS) that are composed predominantly of primitive neuroepithelial cells. Among the different CNS PNET, those arising in the posterior fossa (i.e. medulloblastomas) are prototypical of this group of brain tumors. The basic cell biology of PNET is incompletely understood, but recent studies of human PNET biopsies and cell lines derived therefrom demonstrate that neoplastic cells in human PNET recapitulate many of the phenotypic properties of immature CNS neurons or their progenitors. Based on these findings, it has been possible to develop several animal models of human PNET that will enhance efforts to gain fundamental insights into the induction and progression of PNET. In addition, these model systems will enable emerging gene therapies to be targeted specifically for human PNET. Accordingly, this review summarizes current understanding of the cell biology of human PNET, particularly medulloblastomas, and it highlights the most salient features of representative in vivo model systems of human PNET that are relevant to future studies of these tumors.

Animals↗

PubMed2001

Differentiation, proliferation and apoptosis in primary and recurrent primitive neuroectodermal tumors of childhood.

Primitive neuroectodermal tumors (PNETs) of the CNS are a group of embryonal tumors composed of small undifferentiated or poorly differentiated cells. Infratentorially located PNETs are a synonym for medulloblastomas. In this study 31 PNETs, including 5 recurrent tumors, were examined. All children underwent neurosurgery and chemotherapy according to the HIT and HIT-SKK protocols. The specimens were investigated both for their expression of nine immunohistochemical markers for neuronal, astrocytic, mesenchymal and epithelial differentiation and for their proliferation. Results regarding cellular differentiation were confirmed ultrastructurally. Apoptosis was detected by labeling the 3'OH ends generated by DNA fragmentation and by electron microscopy. Glial differentiation was shown to have a prognostic relevance, with an elevated (twofold) risk of recurrence. Neuronal differentiation also indicated a tendency to poor prognosis. Those tumors that recurred later showed an increased proliferation rate (69%) compared with nonrecurrent tumors (58%). Apoptosis was identified in all tumors examined. The proportion of apoptotic cells could not be related to the effect of therapy. These results indicate that cellular differentiation may be a useful predicative factor for the prognosis of cerebral PNETs.

Adolescent↗

PubMed1994

[A case of primitive neuroectodermal tumor from rib].

Primitive Neuroectodermal Tumor (PNET) is a small round cell malignancy arising in bone and soft tissue. With the progress of immunohisto-chemical and ultrastructural studies, the tumor has getting attention. We report a rare case of PNET arising from rib. A 19-year-old man was admitted to our hospital complaining of chest and back pain. The tumor arised from 5th rib and en bloc resection was performed. Pathological diagnosis was PNET. After the operation, he is doing well, except being treated with chemotherapy (T9-protocol).

Adult↗

PubMed2000

[A rare primitive neuroectodermal tumor: the medulloepithelioma].

Primitive neuroectodermal tumors (PNET) is a name used to describe rare and highly malignant tumors composed of undifferentiated cells resembling germinal or matrix cells of the embryonic neural tube. These tumors occur most commonly in the first decade of life, and have a particular radiological, histological and evolution features. We report a case of a PNET in an 8-year-old boy who presented intracranial hypertension studied with computed tomography scan, which demonstrated a sharply circumscribed expansive mass in the frontoparietal deep white matter, with a large cystic component, which was considered at first as a glial tumor. It was treated by total excision, and the histologic study demonstrated a medulloepithelioma. We studied the concept of PNET and their pathological, radiological and prognostic features.

Brain↗

PubMed1991

Biology of pediatric peripheral neuroectodermal tumors.

The pediatric peripheral neuroectodermal tumors which include neuroblastoma, peripheral neuroepithelioma and Ewing's sarcoma may correspond to distinct neural crest cell lineages or tumors arrested at different stages of neural crest development. Besides a brief commentary on the salient clinical features of these tumors, this review examines how cell and molecular biological studies have contributed to a re-classification of these tumors. The differentiation of these tumors is reviewed with a particular emphasis on retinoic acid induced differentiation of neuroblastoma as a model to identify genes important in controlling cell growth, suppression of tumorigenicity and induction of differentiation.

Adolescent↗

PubMed1997

[Mediastinal neuroectodermal tumor. Apropos of a case].

Peripheral malignant neuroectodermal tumors are rare and aggressive small-cell tumors seen predominantly in children and young adults. Mediastinal location is very uncommon. A mediastinal primitive neuroectodermal tumor was diagnosed in a 27-year-old man. Despite treatment combining surgery, radiotherapy and chemotherapy, disease recurred locally along with lungs, spinal and epidural metastases, leading to death. CT and MRI examinations show heterogeneous masses with necrosis, hemorrhage and intense enhancement after Gadolinium injection. The CT and MRI findings are not specific and the diagnosis is based on pathologic, immunohistochemical and electron microscopic features. Although uncommon, peripheral neuroectodermal tumor should be considered in the differential diagnosis of posterior mediastinal masses in children and young adults.

Adult↗

PubMed1998

Gigantiform melanotic neuroectodermal tumor of infancy.

Melanotic neuroectodermal tumor of infancy is a rare neoplasm of possibly neural crest origin, and it predominantly occurs in the premaxillas of infants less than 12 months old. Generally, the treatment of this benign pigmented lesion is conservative surgical excision. Long-term follow-up is imperative inasmuch as local recurrence and malignant transformation have been reported. A case with exceptional clinical features involving a 7-month-old child is presented.

Female↗

PubMed1999

Comparative genomic hybridization in patients with supratentorial and infratentorial primitive neuroectodermal tumors.

BACKGROUND: Intracranial primitive neuroectodermal tumors (PNETs) occur in the supratentorial and infratentorial regions of the brain. Although histologically similar, the natural history of the tumor at each site differs. The study goal was to determine whether there was evidence of a genetic difference between supratentorial and infratentorial PNETs. METHODS: Using comparative genomic hybridization (CGH), 53 PNETs were analyzed to determine copy number aberrations. Forty-three tumors were located in the cerebellum (IPNETs), and ten were supratentorial PNETs (SPNETs). All samples were reviewed to confirm the diagnosis. Each specimen had at least 50% tumor. RESULTS: Six of the 43 cases of IPNET had no copy number aberrations. In contrast, each case of SPNET had copy number aberrations detected by CGH. Statistically significant differences in copy number aberrations of chromosomes 14, 17, and 19 were detected in the two groups. The most common copy number aberration in the IPNETs was gain of chromosome 17q, which was observed in 16 of 43 cases (37%). However, no case of SPNET had gain of 17q. Loss of 14q was detected in four of ten SPNETs but was not detected in any of the IPNET cases. Loss of 19q was detected in 4 of 10 SPNETs and in only 1 of 43 IPNETs. CONCLUSIONS: These results indicate that the genetic aberrations of IPNETs differ from the genetic aberrations of SPNETs. Although they are similar histologically, SPNETs and IPNETs appear to be biologically distinct entities.

Adolescent↗

PubMed1983

Primitive neuroectodermal tumors of the central nervous system.

Primitive neuroectodermal tumors are morphologically similar malignant tumors arising in intracranial and peripheral sites of the nervous system, showing varying degrees of cellular differentiation with a tendency to disseminate along cerebrospinal fluid pathways. They occur primarily in children and young adults. Under the designation primitive neuroectodermal tumors are included medulloblastomas and tumors that may differentiate in other directions, such as medulloepithelioma, neuroblastoma, polar spongioblastoma, pineoblastoma, ependymoblastoma, retinoblastoma, and olfactory neuroblastoma. From a practical, histologic point of view, these tumors are often indistinguishable from one another and are best thought of as primitive neuroectodermal tumors with or without differentiating features.

Animals↗

PubMed1998

Poorly differentiated synovial sarcoma: immunohistochemical distinction from primitive neuroectodermal tumors and high-grade malignant peripheral nerve sheath tumors.

Synovial sarcoma is a relatively common sarcoma in adults, which in its classic bimorphic form infrequently poses a diagnostic problem. Monomorphic spindled variants, as well as the less common poorly differentiated variants, may be confused with other soft-tissue sarcomas; the poorly differentiated variant (PDSS), in particular, may be histologically indistinguishable from other small, blue, round cell tumors, including primitive neuroectodermal tumors (PNETs). Detection of the synovial sarcoma-associated t(X;18) by either cytogenetic or molecular genetic approaches may be necessary to confirm the diagnosis of synovial sarcoma in difficult cases. We evaluated 10 cases of PDSS from eight patients using a panel of antibodies (including those to intermediate filament proteins, nerve-sheath associated markers, and neuronal and neuroectodermal associated markers) in order to better establish the immunophenotype of this tumor and to help distinguish it from the tumors with which it may be confused, particularly PNETs and high-grade malignant peripheral nerve sheath tumors (MPNSTs). Our results showed PDSS to have significant immunophenotypic overlap with both PNETs and MPNSTs. In most instances these three entities may be differentiated by a panel of antibodies that should include those to both low and high molecular weight cytokeratins, epithelial membrane antigen, type IV collagen, CD99, CD56, and S-100 protein. Our results also suggest that synovial sarcoma may be a tumor showing combined neuroectodermal and nerve sheath differentiation--perhaps because of translocation-associated expression of specific proteins--rather than a carcinosarcoma of soft tissues or a tumor of specialized arthrogenous mesenchyme.

12E7 Antigen↗

PubMed1995

Ewing's sarcoma and extracranial peripheral neuroectodermal tumors.

Ewing's sarcoma and extracranial primitive neuroectodermal tumors of bone and soft tissue are small round-cell tumors that comprise a family of neoplasms distinguished by a cytogenetic marker that can be detected by reverse transcription and polymerase chain reaction. Based on molecular and immunohistochemical studies, it is generally acknowledged that this is a family of neuroectodermal tumors. Molecular methods allow accurate diagnosis with minimally invasive surgical options, provide a manner to detect minimal residual disease, and begin to shed light on the pathogenesis of these entities. Combined modality treatment regimens continue to improve the outlook for nonmetastatic Ewing's sarcoma and primitive neuroectodermal tumors patients. Patients who present with metastatic disease may benefit from intensive therapy as facilitated by peripheral stem cell and autologous bone marrow rescue programs.

Antineoplastic Combined Chemotherapy Protocols↗