Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Neuroectodermal Tumors”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 685 records · Page 38Linked to original sources
PubMed1990

Melanotic neuroectodermal tumor of infancy.

The case of a 2-month-old male infant treated for melanotic neuroectodermal tumor of infancy is presented to demonstrate the importance of early treatment in the containment of the growth of such lesions. Although the lesion itself is rare, the posterior maxillary location and involvement of the optic nerve in this patient's lesion made his case even less typical of those commonly documented in the literature. Complete surgical excision of the lesion was not possible in this patient because of the gross mutilation it would have caused. There was no evidence of the tumor recurring in 18 months of follow-up examinations. These results support the current theories regarding the debulking effect in conjunction with bodily defenses on residual tumor cells and the effect of the removal of stimulatory cells on invading peripheral cells. This case points out the importance of an early and rapid investigation of a mass that initially occurs on the alveolar ridge of an infant.

Humans↗
PubMed1994

Paraffin section p53 protein immunohistochemistry in neuroectodermal tumors.

In an attempt to characterize the role of p53 alterations in the pathogenesis of intracranial neuroectodermal tumors, 196 tumors were immunostained with a monoclonal antibody against the p53 protein on archival materials of formalin-fixed, paraffin-embedded materials. Only 11% of well differentiated astrocytomas stained positive, whereas up to 40% of high-grade astrocytomas (anaplastic astrocytomas and glioblastoma multiforme) were immunolabelled. The extent of immunolabelling of tumor cells also increased from the low-grade to high-grade astrocytomas. Among the high-grade astrocytomas, the small anaplastic cells were the predominant cell type which exhibited aberrant p53 protein accumulation. Rare cases of oligodendrogliomas and medulloblastomas also stained positive, whereas ependymomas and choroid plexus tumors were uniformly negative. p53 alterations therefore appear to play a role in the progression from low-grade to high-grade astrocytomas and the cell type which appeared to be critically involved appeared to be the small anaplastic cells.

Astrocytoma↗
PubMed1986

Primitive neuroectodermal tumor in the skin with features of neuroblastoma in an adult patient.

A case of primitive neuroectodermal tumor of an 81-year-old man is presented, which was located in the cutis. The occurrence in this age and this superficial location is unusual and raises wide differential diagnostic possibilities. The tumor demonstrated Homer Wright rosettes, was positive for neuron-specific enolase and ultrastructurally revealed neurosecretory granules. These features support the diagnosis of a peripheral neuroblastoma. We discuss the controversy about the terminology of peripheral neuroblastoma vs. neuroepithelioma, as well as the differential diagnosis of these tumors.

Aged↗
PubMed1987

Quality of life in children with primitive neuroectodermal tumors (medulloblastoma) of the posterior fossa.

We reviewed our experience in 43 consecutive patients with primitive neuroectodermal tumors (medulloblastoma), PNET (MB), treated between 1975 and 1984, to characterize their quality of life and identify factors which impacted on long-term function. Twenty-four of forty-three (56%) of children are alive and free of disease, a median of 4.5 years after diagnosis. The quality of life was analyzed for the 24 long-term survivors. 79% (19 of 24) were functioning well in everyday activities. The median full-scale intelligence quotient (FSIQ), obtained a median of 3.5 years after diagnosis for those tested (n = 17) was 97, with all but 3 (12%) of the patients functioning in the normal range. Specific learning, memory and fine-motor disabilities were found in over one half of patients. Factors associated with poorer performance and lower FSIQ included preoperative obtundation, the need for a permanent shunt, younger age at diagnosis, and a complicated postoperative course. It is concluded that (1) the majority of long-term survivors have 'normal' intellectual function, but may have specific intellectual and academic disabilities, and (2) preoperative and postoperative factors strongly impact on the quality of life of survivors.

Adolescent↗
PubMed1994

Molecular phenotype of simian virus 40 large T antigen-induced primitive neuroectodermal tumors in four different lines of transgenic mice.

BACKGROUND: We compared the molecular phenotypes of central nervous system tumors arising in four different lines of transgenic mice (TGM) carrying the Simian virus 40 large T antigen driven by different promoters or enhancers. Two of the four lines developed primitive neuroectodermal tumors (PNETs) in the brain stem or pineal gland. A third TGM line developed retinoblastomas (a PNET-like tumor of the retina) as well as PNETs in the mesencephalon, while the fourth TGM developed retinoblastomas and adrenal pheochromocytomas. EXPERIMENTAL DESIGN: The expression of developmentally regulated polypeptides specific for the neuronal or glial lineage was examined in these PNETs using immunohistochemistry and Western blotting. RESULTS: Neoplastic cells in all of the PNETs exhibited neuronal, but no glial specific markers as evidenced by the invariable expression of synaptophysin, but no detectable glial fibrillary acidic protein or myelin basic protein. PNETs with a more differentiated neuronal phenotype expressed multiple neuronal polypeptides. The phenotypic properties of these PNETs closely resembled those found in human brain PNET biopsy samples and cell lines derived therefrom. CONCLUSIONS: We conclude that Simian virus 40 T antigen-induced PNETs in TGM exhibit the molecular phenotype of developing neurons or neuronal progenitor cells. Although many factors could influence the phenotype of these experimental PNETs (e.g., promoter, site of integration of the transgene) these PNETs appear to be suitable TGM models of human PNETs of the central nervous system.

Adrenal Gland Neoplasms↗
PubMed2004

White matter lesions detected by magnetic resonance imaging after radiotherapy and high-dose chemotherapy in children with medulloblastoma or primitive neuroectodermal tumor.

PURPOSE: White matter lesions (WMLs) have been described as a delayed effect of cranial irradiation in children with brain tumors, or a transient subacute effect characterized by an intralesional or perilesional reaction. We report the occurrence of subacute WMLs detected by magnetic resonance imaging (MRI) in children treated for medulloblastoma or primitive neuroectodermal tumor (PNET) and document the associated clinical, radiologic, and neurocognitive findings. PATIENTS AND METHODS: Among 134 patients with medulloblastoma or supratentorial PNET treated prospectively with risk-adjusted craniospinal irradiation and conformal boost to the tumor bed, followed by four high-dose chemotherapy (HDC) cycles with stem-cell rescue, 22 developed WMLs on T1-weighted imaging with and without contrast and/or T2-weighted imaging on MRI. Patients had > or = 12 months of follow-up. Neurocognitive assessments included intelligence quotient (IQ) tests and tests of academic achievement. RESULTS: Twenty-two patients developed WMLs at a median of 7.8 months after starting therapy (range, 1.9 to 13.0 months). Lesions were predominantly in the pons (n = 8) and cerebellum (n = 6). Sixteen patients (73%) had WML resolution at a median of 6.2 months (range, 1.68 to 23.5 months) after onset; two patients developed necrosis and atrophy. Three developed persistent neurologic deficits. Cumulative incidence of WMLs at 1 year was 15% +/- 3%. Patients with WMLs had a significant decline in estimated IQ (-2.5 per year; P = .03) and math (-4.5 per year; P = .003) scores. CONCLUSION: WMLs in medulloblastoma or PNET patients treated with conformal radiotherapy and HDC are typically transient and asymptomatic, and may mimic early tumor recurrence. A minority of patients with WMLs develop permanent neurologic deficits and imaging changes. Overall, the presence of WMLs is associated with greater neurocognitive decline.

Adolescent↗
PubMed1998

Centrosome amplification as a possible mechanism for numerical chromosome aberrations in cerebral primitive neuroectodermal tumors with TP53 mutations.

Although alterations in chromosome number have frequently been detected in human tumor cells and associated with tumor initiation and progression, the causal mechanisms are still not understood. One protein known to be involved in maintaining genetic stability is tumor suppressor p53. In mice, p53 has been implicated in the maintenance of diploidy (Cross et al., 1995) and the regulation of centrosome duplication (Fukasawa et al., 1996). Here we report on cerebral primitive neuroectodermal tumors that lacked the wild-type p53 gene (TP53) and showed multiple numerical chromosome aberrations, as detected by comparative genomic hybridization. In these tumors, the centrosome number was significantly higher than in a control tumor without a detected TP53 mutation and with few chromosomal imbalances. These findings indicate that abnormal centrosome amplification can occur in human tumors lacking wild-type TP53 and may be a mechanism by which numerical chromosome aberrations are generated.

Aged↗
PubMed2003

Adult soft tissue Ewing sarcoma or primitive neuroectodermal tumors: predictors of survival?

BACKGROUND: Ewing sarcoma (ES) is the second most common primary osseous malignancy in childhood and adolescence. The improvement in survival is primarily associated with the combination of surgery and chemotherapy. HYPOTHESIS: Little is known about the outcome of adults with soft tissue ES or primitive neuroectodermal tumors (PNET). Certain prognostic factors from soft tissue sarcomas (tumor size, tumor location, margin status, and initial presentation) in adults (>16 years) with ES/PNET will help to identify factors associated with outcome. METHODS: Between July 1, 1982, and June 30, 2000, we identified 59 adult patients with primary soft tissue ES/PNET. Clinicopathologic factors were correlated with the end points studied: patient factors, tumor factors, pathologic factors, status of surgical margins, adjuvant chemotherapy, and radiation therapy. RESULTS: There were 41 male and 18 female patients, with a median age of 27 years (range, 16-72 years). Median tumor size was 8 cm, with all lesions being high grade. The most common site was the trunk (n = 22), with an even distribution of retroperitoneal, pelvis, buttock, and lower extremity (all n = 5). The median follow-up was 29 months (range, 6-222 months), with local recurrence identified in 13 patients (22%), with a median time to recurrence of 15 months (range, 5-200 months). Overall 5-year survival was 60%. Initial presentation was the only predictor of long-term survival, with primary tumor-only presentation having a 5-year survival of 60% (median not reached) compared with primary tumor plus metastatic disease having a 5-year survival of 33% (median, 17 months) (P =.02). CONCLUSION: Initial presentation of disease represents the only predictor of survival identified in this small group of adult patients with ES/PNET.

Adolescent↗
PubMedDate not supplied

Significant differences in the matrix metalloproteinase expression profiles of spontaneous medulloblastomas/primitive neuroectodermal tumors as compared with their xenografted, established tumor cell line derived counterparts.

Matrix metalloproteinases (MMP) are a family of zinc-dependent enzymes which degrade various components of the extracellular matrix (ECM) and play an important role in facilitating neoplastic cell invasion and metastasis. Structural changes in the extracellular matrix are necessary for cell migration during tissue remodeling and tumor invasion. Expression of MMP-2, -3, -9, -10, and -13 was investigated in both spontaneous and xenografted (cells derived from an established cell-line [DAOY#3]) childhood medulloblastomas (MEDs)/primitive neuroectodermal tumors (PNETs) employing an indirect alkaline phosphatase conjugated immunocytochemical technique. Evaluation of the results was based on (a) the percent of neoplastically transformed tissue that reacted positively and (b) a measure of staining intensity [graded from A (highest) to D]. The two forms of stromelysin (SL), types 1 (MMP-3) and 2 (MMP-10), share 82% sequence homology, but exhibit differences in cellular synthesis and inducibility by cytokines and growth factors in vitro. Strong overall expression of MMP-3 and -10 was found only in the spontaneous MEDs/PNETs, especially in the ECM adjacent to blood vessels. Positive immunoreactivity could be seen for these two MMPs in the ECM surrounding over 90% of the neoplastically transformed cells in the spontaneous cases, and the staining intensity was also the strongest possible (A,B). Focal (surrounding less than 10% of the neoplastically transformed cells) but strong (A,B) immunoreactivity for collagenase-3 (MMP-13) was also only detected in spontaneous MEDs/PNETs, an endopeptidase characterized by a potent degrading activity against a wide spectrum of substrates. Weak (surrounding anywhere between 10% and 90% of the neoplastically transformed cells, and of B and B,C intensity) expression of MMP-2 (gelatinase A) and MMP-9 (gelatinase B), two cytokine-induced MMPs, was also observed in the spontaneous cases. Staining for MMP-2 was negative in the xenografted MEDs/PNETs. The only positive immunoreactivity in the xenografted MEDs/PNETs was observed in the case of MMP-9, with expression of strong intensity in the ECM surrounding over 90% of the neoplastically transformed xenografted MED/PNET cells (++++; A,B). It is clear that the activation of MMPs and their inhibitors occurs in a very well orchestrated manner. The data presented here suggest that there are significant differences in the pathophysiology of spontaneous and xenografted human neoplasms, which further establishes the already detected limitations of such models in preclinical cancer research.

Adolescent↗
PubMed1997

Thyroid dysfunction as a late effect in survivors of pediatric medulloblastoma/primitive neuroectodermal tumors: a comparison of hyperfractionated versus conventional radiotherapy.

BACKGROUND: Primary hypothyroidism is a common sequela of craniospinal radiotherapy in the treatment of pediatric brain tumors. METHODS: The authors compared the incidence of primary hypothyroidism after hyperfractionated radiotherapy (HFRT) (n = 14 patients) versus conventionally fractionated radiotherapy (CRT) (n = 34 patients) in a group of pediatric patients with medulloblastoma/primitive neuroectodermal tumors (MB/PNET). RESULTS: The mean age at the time of tumor diagnosis was 7.9 years in the HFRT group and 8.4 years in the CRT group. The patients were followed for a mean of 4.6 years (HFRT) and 8.3 years (CRT) after diagnosis. Mean radiation doses to the thyroid were similar in both radiotherapy groups (29 gray [Gy] [HFRT] vs. 24 Gy [CRT]). Approximately 14% of the HFRT and 62% of the CRT patients developed primary hypothyroidism within a similar period after irradiation (3.2 years [HFRT] vs. 3.0 years [CRT]). Analysis by cumulative incidence function demonstrated a significant difference in the risk of developing thyroid dysfunction between these two groups of patients (P = 0.02). CONCLUSIONS: The current study findings suggest that the use of HFRT in the treatment of pediatric patients with MB/PNET is associated with a lower risk of these patients developing primary hypothyroidism.

Adolescent↗
PubMed1999

Documentation of EWS gene rearrangements by fluorescence in-situ hybridization (FISH) in frozen sections of Ewing's sarcoma-peripheral primitive neuroectodermal tumor.

Prompt and accurate diagnosis of small round cell tumors warrants ancillary studies. Recently, two-color fluorescence in-situ hybridization (FISH) using probes for specific gene rearrangements has gained wide acceptance. EWS gene rearrangements, present in essentially 100% of Ewing's Sarcoma/peripheral primitive neuroectodermal tumor, were evaluated by FISH on frozen sections (FS) of tumor biopsies from 10 patients, plus a negative control, and in seven other malignant neoplasms of childhood. 4mu FS were hybridized overnight, using a single EWS gene-specific probe spanning the EWS breakpoint. We identified EWS rearrangements in 8 of 10 cases (80%) of Ewing's Sarcoma/pPNET. There are no known false positives in diploid or near-diploid tumors, or in any of the non-EWS tumors tested; the uncommon false negative can be confirmed by RT-PCR. Hyperdiploid cases with multiple copies of chromosome 22 may be better evaluated by two-color FISH. This is the first use on FS biopsy material of a single probe for EWS, capable of detecting all known EWS rearrangements, in ES and other tumors. Utilization of this ancillary technique on FS for ES/pPNET and other tumors with distinctive chromosomal translocation is highly specific, reliable, expeditious (24-36 hours) and cost-effective.

Chromosomes, Human, Pair 11↗
PubMed1998

FDG imaging of spinal cord primitive neuroectodermal tumor.

PET with 18F-fluoro-2-deoxy-glucose (FDG) is well established as an effective imaging modality for evaluating suspected brain tumor recurrence. Use of FDG PET imaging for spinal cord neoplasms has not yet been studied, in large part due to limitations of spatial resolution. One report of FDG PET imaging of brain involvement with primitive neuroectodermal tumor (PNET) demonstrated mild hypometabolism relative to cortical gray matter. We demonstrate with FDG PET imaging the appearance of recurrent intramedullary PNET affecting the cervical spinal cord.

Adult↗
PubMed2003

Evaluation of dietetic intervention in children with medulloblastoma or supratentorial primitive neuroectodermal tumors.

BACKGROUND: Malnutrition is a common complication of cancer treatment; it can affect energy levels and, as a consequence, quality of life. The goal of the current study was to evaluate the effect of dietetic intervention in a cohort of children treated for medulloblastoma and supratentorial primitive neuroectodermal tumors (PNET) over a 10-year period. METHODS: A retrospective chart review (1992-2002) of newly diagnosed cases of medulloblastoma/supratentorial PNET was performed. Hospital records were reviewed for data, including demographic characteristics, patient heights and weights, and information on treatment modalities and the use of dietetic intervention. Percent changes in body weight were calculated at time points associated with particular stages of treatment or dietetic intervention. RESULTS: One hundred three of 112 cases were evaluable. Treatment methods included surgery only (7.8%), surgery + radiotherapy (16.5%), surgery + chemotherapy (14.5%), and surgery + radiotherapy + chemotherapy (61.2%). There was no significant change in patient weight due to surgery (median change in body weight [MCBW], -0.35%) or radiotherapy (MCBW, -0.78%). In contrast, children experienced significant weight loss (MCBW, -4.35%; P < 0.0001) 3 months after starting chemotherapy. A dietician saw 53 of the 103 children in the study cohort. There were 84 dietetic interventions (oral, 36%; parenteral, 27%; enteral, 37%) among these 53 patients. Oral diets did not result in weight gain. Parenteral nutrition was associated with significant weight gain at 1 month (MCBW, +2.7%; P = 0.03), but not at 3 months. The use of enteral feeds resulted in significant weight gain at 1 month (MCBW, +4.8%; P = 0.006) and at 3 months (MCBW, +11.8%; P < 0.0001). CONCLUSIONS: Current multimodality treatment of intracranial PNET results in significant nutritional morbidity, primarily due to the use of intensive chemotherapy regimens. Dietetic input for pediatric patients with medulloblastoma/PNET is essential, and the implementation of enteral feeding in these children can help to reverse their nutritional morbidity.

Adolescent↗
PubMedDate not supplied

Role of MAP kinase pathways in primitive neuroectodermal tumors.

Mitogen-activated protein kinase and Phosphatidylinositol-3 kinase/Akt-mediated signaling pathways play a major role in controlling cell proliferation, differentiation and cell death. Phosphorylation and dephosphorylation of their specific Thr/Tyr residues is critical in determining their activity. We determined the expression pattern and activity of MAP kinases and Akt in Primitive Neuroectodermal Tumors (PNETs). The kinase activity of extracellular signal-regulated kinase (ERK) was higher in both primary tumors and cell lines, as evident from the increased phosphorylation of ERK1 and ERK2. We did not observe the activation of C-jun N-terminal kinase (JNK) or p38 MAPK The expression of Raf-1, a kinase acting upstream of ERK, was significantly increased in primary tumors compared to normal brain. The PI-3 kinase-activated phosphorylation of Akt was also higher in primary tumors. These results suggest that activation of the Raf-1/ERK module of the MAP kinase pathway play an important role in PNETs.

Brain Neoplasms↗