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Ectopic intrapelvic medulloepithelioma: case report.

A primary extraspinal medulloepithelioma with lung metastases is reported. The tumour was located in the presacral area. Microscopically, it showed typical features of medulloepithelioma with focal ependymal differentiation. Medulloepitheliomas are malignant tumours of primitive neuro-epithelium usually involving the cerebral hemispheres. This report demonstrates their possible extraspinal presacral occurrence. By immunohistochemistry, neuron-specific-enolase, S100 protein, vimentin, cytokeratin and glial fibrillary acidic protein were found in some tumour cells. Electron microscopy demonstrated poorly differentiated cells forming stratified epithelium resting on a basal lamina and short junctional complexes at the apical pole. Ultrastructural evidence of ependymal differentiation was observed. Presacral medulloepithelioma may arise from undifferentiated embryonic cells forming the presacral remnants of the neurenteric canal.

Adolescent↗

Olfactory neuroblastoma--management of a rare tumour at the Queensland Radium Institute and literature review.

Olfactory neuroblastoma (esthesioneuroblastoma) is an extremely rare tumour arising from the olfactory epithelium of the nasal cavity close to the cribriform plate. Most institutions will have little experience in recognising the clinical and histological features, or management of this tumour and reliance is placed on researching the literature when the individual patient presents. This study reviews seven patients with olfactory neuroblastoma treated at the Queensland Radium Institute from 1971 to January 1990. The overall local control rate in this series is 57% (four of seven patients) and 43% of patients (three of seven) remain alive. Conservative surgery and post-operative radiotherapy is recommended for early disease and more radical surgery with post-operative radiotherapy for advanced disease.

Adult↗

Olfactory neuroepithelioma: an immunohistochemical and ultrastructural study.

Three cases of olfactory neuroepithelioma are presented in this report. Histologically, these tumors were composed of small cells with round to oval, relatively hyperchromatic nuclei and scanty cytoplasm. The tumor cells were occasionally observed in tubular formations or rosette-like arrangements. Immunohistochemically, the tumor cells showed a positive reaction for cytokeratin AE1, cytokeratin CAM5.2, Ber-EP4, antisynaptophysin and anti-S100 protein in all cases. In two cases, LH-RH was detected in the tumor cells. Ultrastructurally, the tumor cells had the differentiation features of olfactory epithelium. Olfactory neuroepithelioma is a rare occurrence and it can be very difficult to distinguish olfactory neuroepithelioma from small cell carcinoma, neuroendocrine carcinoma and so-called "olfactory neuroblastoma" on the basis of hematoxylin and eosin stained sections alone. In controversial cases, a diagnosis of olfactory neuroepithelioma must be substantiated by ultrastructural and immunohistochemical findings, particularly regarding the detection of Ber-EP4 and LH-RH immunoreactivity.

Adolescent↗

Primitive neuroectodermal tumor (neuroepithelioma) of spinal nerve root -- Report of an adult case and establishment of a cell line.

A case of primitive neuroectodermal tumor arising in the cervical nerve root of a 28-year-old man is presented. Histologically, the tumor was characterised by proliferation of primitive neuroectodermal cells and formation of numerous Homer-Wright type rosettes. A cell line (Nagai line) was established from the tumor. Electron microscopic examination of Nagai cells revealed numerous microrosette formation with microvilli-like cytoplasmic processes projecting into the central lumina. Neurosecretory granules appeared in the cytoplasmic processes when Nagai cells were treated with dibutyryl cyclic AMP. Primitive satellite cells which completely surrounded other tumor cells with their tongue-like slender cytoplasmic processes were also found. Histogenesis of this unique tumor was discussed comparing with the neuroblastoma of sympathetic nervous system, medulloblastoma of the central nervous system, and with the tumors induced by Adenovirus type 12 in animals. It was concluded that the tumor was neuroepithelioma derived from a primitive stem cell of neural crest origin which possesses the bipotency to differentiate toward either neuroblastic or neurilemmal line.

Adult↗

Small cell carcinoma of the ovary: a case report of large cell variant.

An extremely rare case of large cell variant of ovarian small cell carcinoma is described. A 34-year-old woman (gravida 1, para 1) had a unilateral ovarian mass measuring 17cm in greatest diameter and a metastatic lesion in the omentum. Microscopically, the tumor showed a diffuse arrangement of large, closely packed epithelial cells with abundant eosinophilic cytoplasm and large nuclei with prominent nucleoli. The tumor cells also were arranged in follicle-like and trabecular structures and cords. Immunohistochemically, many tumor cells were diffusely positive for epithelial membrane antigen and some cells contained cytokeratin CAM5.2, vimentin, neurofilament, neuron-specific enolase, or alpha-1 antitrypsin. However, no specific lineage was detected. The tumor was aneuploid by flow cytometry. The patient received chemotherapy postoperatively. However, the patient showed metastases in the inguinal and retroperitoneal lymph nodes. The serum calcium level, which was not measured preoperatively, was mildly elevated postoperatively. The patient was well with no evidence of disease 17 months after diagnosis. This tumor must be distinguished from other primary or metastatic 'undifferentiated' neoplasms, especially ovarian small cell carcinoma of pulmonary type and granulosa cell tumor.

Adult↗

A case of dysembryoplastic neuroepithelial tumor of the parietal lobe with characteristic magnetic resonance imaging.

The case of a 4 year old boy with a dysembryoplastic neuroepithelial tumor (DNT) of the left parietal lobe is reported. The DNT was located mainly in the cortex and showed no mass effect on magnetic resonance imaging (MRI). T1-weighted images of the DNT showed the characteristic findings of lesion hypointensity, but with a well preserved gyrus-like configuration. This lesion was isointense to the normal cortex on proton density imaging and hyperintense on T2-weighted imaging. The characteristic features on T1-weighted and proton density imaging in this patient were useful in differentiating DNT from other types of tumors. Histologic findings in DNTs, which include the presence of both glial and neuronal cells without atypia and no definite transitional zone between the adjacent disorganized cortical cell layers, suggest that DNT is not a true neoplasm but rather a dysplastic lesion. It is clinically important to differentiate this tumor both from other benign tumors and malignant tumors which have different prognoses and therapies. The distinctive MRI findings, as well as the histologic features of DNT, support the diagnosis in the clinical setting.

Brain Neoplasms↗

Identification of multiple phosphoinositide-linked receptors on human SK-N-MC neuroepithelioma cells.

The biochemical and pharmacological characteristics of receptor-stimulated phosphoinositide (PPI) hydrolysis in human SK-N-MC neuroepithelioma cells have been examined. Of 11 ligands tested, the addition of four, i.e., norepinephrine, oxotremorine-M, endothelin-1, and ATP, each resulted in an increased release (three- to eightfold) of inositol phosphates from [3H]inositol-prelabeled cells. Agonist-stimulated PPI turnover was sustained for at least 30 min and required the addition of Ca2+ for full effect. An increased release of inositol phosphates could also be elicited by the addition of the Ca2+ ionophore, ionomycin. All four agonists enhanced the release of radiolabeled inositol mono- and bisphosphates, inositol 1,3,4-trisphosphate, and inositol tetrakisphosphate. Increases in inositol 1,4,5-trisphosphate were smaller and only consistently observed in the presence of norepinephrine or oxotremorine-M. Norepinephrine-stimulated PPI turnover was potently inhibited by prazosin, WB-4101, and 5-methylurapidil (Ki less than 2.5 nM), but was relatively insensitive to chlorethylclonidine pretreatment. This pharmacological profile is consistent with the involvement of an alpha 1A-receptor subtype. The presence of an M1 muscarinic cholinergic receptor is also indicated, because pirenzepine blocked oxotremorine-M-stimulated inositol phosphate release (Ki = 35 nM) with a 30-fold greater potency than the M2-selective antagonist, AF-DX 116. Of the three endothelins tested, only the addition of endothelin-1 and endothelin-2 promoted PPI hydrolysis, whereas endothelin-3 was essentially inactive. A P2 nucleotide receptor of broad agonist specificity is also present on these cells and activates PPI turnover in the absence of a generalized increase in plasma membrane permeability. These results indicate that SK-N-MC cells express at least four PPI-linked receptors. Because the functional coupling of three of these receptors, i.e., alpha 1A-adrenergic, endothelin, and P2 nucleotide, has not been extensively characterized previously in neural tissues, the SK-N-MC cell line may provide a useful model system for studies of these receptors and their regulation.

Adrenergic Agonists↗

Characterization and regulation of beta 1-adrenergic receptors in a human neuroepithelioma cell line.

Intact human neuroepithelioma SK-N-MC cells bound the beta-adrenergic antagonist (-)-[3H]-CGP 12177 with a KD of 0.13 nM and a Bmax of 17,500 sites/cell. When the cells were exposed to beta-adrenergic agonists, they accumulated cyclic AMP in the following order of potency: isoproterenol much greater than norepinephrine greater than epinephrine, which is indicative of a beta 1-subtype receptor. Membranes prepared from the cells bound (-)-3-[125I]iodocyanopindolol with a KD of 11.5 pM. Inhibition of agonist-stimulated cyclic AMP production and competition binding experiments indicated that the beta 1-selective antagonists CGP 20712A and ICI 89,406 were much more potent than the beta 2-selective antagonist ICI 118,551. Analysis of the displacement curves indicated that the cells contained only beta 1-adrenergic receptors. Northern blot analysis of SK-N-MC mRNA using cDNA probes for the beta 1- and beta 2-adrenergic receptors revealed the presence of a very strong beta 1-adrenergic receptor mRNA signal, while under the same conditions no beta 2-adrenergic receptor mRNA was observed. Thus, SK-N-MC cells appear to express a pure population of beta 1-adrenergic receptors. When the cells were exposed to isoproterenol, there was no observable desensitization during the first hour. After longer exposure, desensitization slowly occurred and the receptors slowly down-regulated to 50% of control levels by 24 h. Other agents that elevate cyclic AMP levels, such as forskolin, cholera toxin, and cyclic AMP analogues, caused no or little substantial receptor loss.

Adrenergic beta-Antagonists↗

Integration of G protein signals by extracellular signal-regulated protein kinases in SK-N-MC neuroepithelioma cells.

Mammalian cells often receive multiple extracellular stimuli under physiological conditions, and the various signaling inputs have to be integrated for the processing of complex biological responses. G protein-coupled receptors (GPCRs) are critical players in converting extracellular stimuli into intracellular signals. In this report, we examined the integration of different GPCR signals by mitogen-activated protein kinases (MAPKs) using the SK-N-MC human brain neuroepithelioma cells as a neuronal model. Stimulation of the Gi-coupled neuropeptide Y1 and Gq-coupled muscarinic M1 acetylcholine receptors, but not the Gs-coupled dopamine D1 receptor, led to the activation of extracellular signal-regulated kinase (ERK). All three receptors were also capable of stimulating c-Jun NH2-terminal kinases (JNK) and p38 MAPK. The Gi-mediated ERK activation was completely suppressed upon inhibition of Src tyrosine kinases by PP1, while the Gq-induced response was suppressed by both PP1 and the Ca2+ chelator, BAPTA-AM. In contrast, activations of JNK and p38 by Gs-, Gi-, and Gq-coupled receptors were sensitive to PP1 and BAPTA-AM pretreatments. Simultaneous stimulation of Gi- and Gq-coupled receptors resulted in the synergistic activation of ERK, but not JNK or p38 MAPK. The Gi/Gq-induced synergistic ERK activation was PTX-sensitive, and appeared to be a co-operative effect between Ca2+ and Src family tyrosine kinases. Enhanced ERK activation was associated with an increase in CREB phosphorylation, while the JNK and p38-responsive transcription factor ATF-2 was weakly enhanced upon Gi/Gq-induction. This report provides evidence that G protein signals can be integrated at the level of MAPK, resulting in differential effects on ERK, JNK and p38 MAPK in SK-N-MC cells.

Adenylyl Cyclases↗

Coexistence of neoplasia and cortical dysplasia in patients presenting with seizures.

Tumors and cortical dysplasia are associated with epilepsy, but few studies have examined the coexistence of neoplasia and dysplasia in these patients. We studied 13 patients (age 4-29 years) with recurrent seizures of 1 month to 21-year' duration (median 72 months). Ten patients were aged < 21 years. Imaging studies localized the lesion to the temporal lobe (10 patients), parietal lobe (2 patients), and frontal lobe (1 patient). Tumors included ganglioglioma (8 patients), dysembryoplastic neuroepithelial tumor (DNT) (3 patients), and low-grade astrocytoma (2 patients). Cortical dysplasia, including atypical aggregates of neurons (6 patients), multifocal loss of the cortical laminar architecture (7 patients), and neurons in the molecular layer of the cortex (3 patients) were observed near but separate from the tumor. Coexistence of certain tumors with cortical dysplasia, most frequently observed in the pediatric population, suggests a hamartomatous/dysplastic nature of the neoplasms.

Adolescent↗

Psychosis after resection of ganglioglioma or DNET: evidence for an association.

PURPOSE: David Taylor and Murray Falconer suggested that some patients may develop a psychotic illness after resection of a ganglioglioma that led to intractable seizures. They implied that the mechanism of this association remained unclear. This concept is currently not universally accepted (M. Trimble, personal communication). METHODS: We studied six children or young adults from four centers who developed psychosis after resection of a ganglioglioma or dysembryoplastic neuroepithelioma (DNET). RESULTS: All patients were operated on because of intractable epilepsy. The lesions involved mainly the temporal lobe. Patients had good outcomes for seizure control. In none of the six was potentially psychogenic medication used nor were the psychotic symptoms postictal in nature. The psychosis was schizophreniform with paranoid features and prominent depressive symptoms. Although some behavioral abnormalities were described preoperatively, none had been psychotic before operation. This type of psychotic reaction was not encountered in the four centers in a comparable period after resection of other types of lesions. This complication is rare; it occurred in only one of 39 patients who had such a lesion resected. CONCLUSIONS: Psychotic illness may rarely occur after resection of a ganglioglioma or DNET for treatment of intractable epilepsy. This does not seem to occur after removal of other types of lesions. Because the patients had good outcomes for seizures, the mechanism may be related to "forced normalization." The original observations of Taylor and Falconer are confirmed by this study; the reasons for the selective occurrence, however, remain speculative.

Adolescent↗