Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Neuroectodermal Tumors, Primitive”

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 181 records · Page 10Linked to original sources
PubMed1996

Olfactory neuroblastoma is a peripheral primitive neuroectodermal tumor related to Ewing sarcoma.

Olfactory neuroblastoma (ONB) is a malignant tumor of the nasal mucosa whose histogenesis is unclear. A relationship to neuroblastoma (NB), a pediatric tumor of the sympathetic nervous system, is based on morphologic similarities and the expression of similar neural antigens. However, the clinical presentation of ONB differs from that of NB, and MYCN amplification characteristic of NB is not observed. We have therefore examined the relationship of this malignancy to other classes of neural tumors. In previous studies, two ONB cell lines demonstrated cytogenetic features and patterns of protooncogene expression suggestive of a relationship to the Ewing sarcoma family of childhood peripheral primitive neuroectodermal tumors (pPNETs). The pPNETs show t(11;22)(q24;q12) or t(21;22)(q22;q12) chromosomal translocations fusing the EWS gene from 22q12 with either the FL11 gene on 11q24 or the ERG gene on 21q22. We therefore analyzed ONBs for the presence of pPNET-associated gene fusions. Both cell lines showed rearrangement of the EWS gene, and fluorescence in situ hybridization (FISH) of each case demonstrated fusion of EWS and FL11 genomic sequences. Moreover, both lines expressed EWS/FL11 fusion transcripts with in-frame junctions between exon 7 of EWS and exon 6 of FL11 as described for pPNETs. We identified similar gene fusions in four of six primary ONB cases. None of the cases expressed tyrosine hydroxylase, a catecholamine biosynthetic enzyme widely expressed in NB. Our studies indicate that ONB is not a NB but is a member of the pPNET family.

Adult↗
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↗
PubMed1989

N-myc amplification and neuronal differentiation in human primitive neuroectodermal tumors of the central nervous system.

Despite the phenotypic similarities between primitive neuroectodermal tumors of the central nervous system, childhood neuroblastoma, and peripheral neuroepithelioma, a histogenetic relationship among these neoplasms has not been shown. High levels of N-myc expression occur selectively in developing brain and in some embryonic tumors of neural origin. N-myc amplification and high levels of N-myc expression in childhood neuroblastoma have been correlated with disease stage and prognosis. To determine whether the copy number of the N-myc gene in primitive neuroectodermal tumors of the central nervous system is altered, we examined 20 primitive neuroectodermal tumors by Southern and/or slot blot hybridization to a 1-kilobase N-myc genomic DNA sequence and a 492-base pair N-myc-specific subclone as well as to a 1.1-kilobase albumin complementary DNA sequence as a control for gene copy number. Amplification of the N-myc gene was detected in two cerebellar tumors both of which exhibited neuronal differentiation by light microscopy. These tumors had not been treated previously. Of the remaining 18 tumors, eight were undifferentiated, three showed early neuroblastic, and seven focal glial differentiation. These findings suggest a possible relationship between N-myc amplification and neuronal differentiation.

Brain Neoplasms↗
PubMed1996

Peripheral neuroepithelioma (peripheral primitive neuroectodermal tumor) of the uterine cervix.

We report here a case of peripheral neuroepithelioma arising in the uterine cervix. A 44-year-old female had complained of irregular genital bleeding for several months and was diagnosed as extraosseous Ewing's sarcoma (EOE) from biopsy specimens initially. The tumor cells, which were intensely stained by periodic acid-Schiff (PAS) and digested with diastase, were uniformly small and round, had hyperchromatic nuclei and scant, indistinct cytoplasm. The surgically-removed tumor cells were immunohistochemically stained with antisera against neuro-specific enolase (NSE), tyrosine hydroxylase. In ultrastructural study, neurosecretory granules were observed. Finally we diagnosed this case as peripheral neuroepithelioma (peripheral primitive neuroectodermal tumor, PNET).

Adult↗
PubMed2000

In situ reverse-transcriptase polymerase chain reaction demonstration of the EWS/FLI-1 fusion transcript in Ewing's sarcomas and peripheral primitive neuroectodermal tumors.

It is now widely accepted that the EWS/FLI-1 fusion transcript is associated with tumors of the Ewing family. To test whether it is possible to detect the fusion transcript by means of combining polymerase chain reaction (PCR) methodology and immunohistochemistry, we investigated tumors of the Ewing family using in situ reverse transcriptase (RT)-PCR. We were able to demonstrate the t(11;22) fusion transcript in five of six cases of Ewing's sarcoma and four of four peripheral primitive neuroectodermal tumors. These results were confirmed using fluorescence in situ hybridization in seven tumor samples. In situ RT-PCR-labeled fusion transcripts were found in virtually all tumor cells within a given sample, indicating that each cell possessed the t(11;22) transcript. We conclude from these results that in situ RT-PCR can be used for the rapid detection of EWS/FLI-1 fusion transcripts in biopsy material. The findings also suggest that all cells of the tumors of the Ewing family carry the EWS/FLI-1 fusion transcript.

Adolescent↗
PubMed1998

[Differential diagnosis of distal peripheral nerve compression syndrome of the tibial nerve. Case report of primitive neuroectodermal tumor].

Tumors of the tibial nerve are not sufficiently taken into account in the diagnosis of tarsal tunnel syndromes (TTS). They may present with atrophy of the plantar flectors and with disturbances of sensory functions, but far more commonly with pain. Diagnosis is often only achieved after 1-2 years. Taking tumors into account when examining patients presenting with TTS may lead to a more rapid diagnosis and to improvement in patients' prognoses. We present the case of a 37-year-old female in whom a primitive neuroectodermal tumor (PNET) was found to be the cause of long-standing pain in the right foot.

Adult↗
PubMed2004

Primitive neuroectodermal tumor of the head and neck: incidence, diagnosis, and management.

Primitive neuroectodermal tumors are in the Ewing's sarcoma family of tumors and are composed of small round cells. Because of their rare occurrence, optimal therapy is challenging, particularly if they occur in the head and neck. Diagnosis is based on history, immunostaining with at least 2 neural markers, ultrastructural examination, and evidence of an abnormal t(11;22)(q24;q12) translocation as the hallmark for the Ewing's sarcoma family. The prognosis in general is poor because of overt metastasis at the time of diagnosis. Of 27 reported patients with primitive neuroectodermal tumors of the head and neck, 23 were less than 20 years of age. Most patients presented with a tumor in the nasal cavity, paranasal sinuses, or neck. Symptoms developed rapidly (3.6 months, on average), and a lethal outcome occurred in 9 patients. This highly malignant tumor requires an aggressive combination of radical resection, chemotherapy, and radiotherapy. A close follow-up with regular radiographic examination for at least 5 years is mandatory.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2001

Prognostic significance of Ki-67 (MIB-1) proliferation index in childhood primitive neuroectodermal tumors of the central nervous system.

BACKGROUND: Primitive neuroectodermal tumors (PNET) of the central nervous system, including medulloblastomas, are the most common malignant brain tumors of childhood. Whereas some patients experience prolonged disease control after surgery and adjuvant therapy, others with tumors that appear comparable will relapse and eventually die from progressive disease. PROCEDURE: Because proliferative activity may provide a potential correlate of biologic aggressiveness, PNETs of 78 well-characterized patients were evaluated by Ki-67 (MIB-1) immunohistochemistry. Proliferation indices (PI) were determined by counting Ki-67 (MIB-1) positive tumor cells either in the highest staining region (hot spot PI), or in at least 15 randomly chosen fields (random PI). RESULTS: Twenty-five of 78 PNETs showed amore than twofold higher value of hot spot PI (median 9.3%; range 0.6-56%), compared to random PI (median 5.6%; range 0.2-41.3%), Univariate Cox regression analysis revealed that PNETs with a high hot spot PI had a significantly greater risk of progression and death than PNETs with a low hot spot PI (hazard ratio 1.58, P = 0.04). The hazard ratio remained significant after adjusting for M-stage in multivariate analysis. In contrast to hot spot PI, random PI proved not to be a significant prognostic predictor. CONCLUSIONS: Hot spot PI is a significant and independent prognostic factor in PNETs. Its assessment is uncomplicated, reliable, and may supplement routine histologic examination as a means for improving the accuracy of predicting the biologic behavior of childhood PNETs.

Adolescent↗
PubMed2005

[Orbital primitive neuroectodermal tumor with intracranial extension. A case report].

Primitive neuroectodermal tumor (PNET) of the orbit is rare. We present a case of a young patient with orbital PNET extending to the endo-crane and sinuses, which had been treated 10 years before with the diagnosis of rhabdomyosarcoma. The diagnosis was corrected with immunohistochemistry. Through this observation, we discuss the clinical aspects, the diagnosis difficulties, and the therapeutic options of this rare affection.

Adult↗
PubMed2001

Primitive neuroectodermal tumor of the kidney: a rare entity.

Primitive neuroectodermal tumor (PNET) is usually aggressive and rapidly progressing and metastasizing tumor. Occurrence of the this type of tumor in the kidney is considered as unusual, and few cases have been reported so far. We present a PNET arising from the kidney in a 23-year-old female patient.

Adult↗
PubMed2001

Metastatic primitive neuroectodermal tumor of the kidney in adults.

OBJECTIVE: Primitive neuroectodermal tumors (PNET) of the kidney are rare and highly aggressive malignancies. The purpose of our study was to present information about the management of patients with metastatic disease. METHODS: The records of 2 patients (30-year-old female and 32-year-old male) with metastatic PNET of the kidney were reviewed and our data compared with the literature. RESULTS: Neither clinical evaluation nor radiological methods allowed to distinguish PNET from renal cell carcinoma. Immunohistochemistry revealed strong positivity for CD99 in tumor 1 and weak positivity for NSE and vimentin in both tumors. In tumor 2, EWS/FLI1 translocation was detected by RT-PCR. Patient 1 underwent nephrectomy, seven cycles of polychemotherapy, two cycles of high-dose chemotherapy, autologous bone marrow rescue, radiotherapy of suspicious skeletal foci and is without evidence of recurrent disease 28 months after therapy. Patient 2 underwent six cycles of polychemotherapy, nephrectomy, high-dose chemotherapy with cyclophosphamide and abdominal radiotherapy. Because of relapse high-dose chemotherapy with stem cell rescue was not performed. He underwent three further cycles of polychemotherapy and died one year after diagnosis due to cerebral metastasis. CONCLUSIONS: The diagnosis of renal PNET must be considered in young patients with renal neoplasm, particularly those with advanced disease at presentation. Achieving exact diagnosis has important clinical consequences because polychemotherapy and high-dose chemotherapy may lead to dramatic tumor reduction or even complete remission.

12E7 Antigen↗
PubMed2005

Primitive neuroectodermal tumor of the kidney with hyaline cells.

Primitive neuroectodermal tumor (PNET) of the kidney is a rare disease with high malignant potential. It affects young adults and has the tendency towards early metastasis. Relying on recently available immunohistochemistry and cytogenetic investigations, today most authors define PNET as part of the same nosologic entity as Ewing's sarcoma. We present the case of a 22-year-old man with a PNET arising from the kidney with, to our knowledge, a previously undescribed finding of hyaline cells within the tumor.

Adult↗
PubMedDate not supplied

High-dose anthracyclines in the treatment of advanced primitive neuroectodermal tumors in adults--a single institution experience.

Primitive neuroectodermal tumors (PNET) are rare malignancies of presumed neural crest origin, most often presenting as bone or soft tissue masses in the trunk or axial skeleton, in children and young adults. Treatment of advanced PNET in adults is not clearly defined in the literature. Data concerning dose-intensive chemotherapy regimens for poor-risk patients with those tumors are sparse, due to rarity of PNET in adults, their diverse presentation, the variable treatment procedures applied and the absence of direct comparisons. On the other hand, the role of anthracyclines in the treatment of advanced soft tissue sarcomas is well known and substantial. Six advanced PNET patients were treated at the Institute for Oncology and Radiology of Serbia, during last five years, with high-doses of doxorubicin or epidoxorubicin combined with cisplatin. The paper reviews each of our patients, discussing how does chemotherapy influence the outcome in these patients, in context of the feasibility of high-doses of anthracyclines in advanced settings. High dose anthracyclines (epidoxorubicin 150 mg/m2) in combination with cisplatin 120 mg/m2 induced a complete response lasting for 63+ months in a patient with desmoplastic medulloblastoma of the cerebellum metastatic to bones and bone marrow. The same treatment but with the epidoxorubicin dose of 180 mg/m2 induced a complete response in a patient with olfactory neuroblastoma. Administration of high dose Doxorubicin (75 mg/m2) seems feasible in association with irradiation treatment in patients with extraosseal Ewing sarcoma/PNET but the place of high dose chemotherapy within this setting remains to be determined.

Adult↗
PubMedDate not supplied

Dynamic susceptibility contrast-enhanced perfusion and conventional MR imaging findings for adult patients with cerebral primitive neuroectodermal tumors.

BACKGROUND AND PURPOSE: Preoperative differentiation of primitive neuroectodermal tumors (PNETs) from other tumors is important for presurgical staging, intraoperative management, and postoperative treatment. Dynamic, susceptibility-weighted, contrast-enhanced MR imaging can provide in vivo assessment of the microvasculature in intracranial mass lesions. The purpose of this study was to determine the perfusion characteristics of adult cerebral PNETs and to compare those values with low and high grade gliomas. METHODS: Conventional MR images of 12 adult patients with pathologically proved cerebral PNETs were analyzed and provided a preoperative diagnosis. Relative cerebral blood volume (rCBV) measurements and estimates of the vascular permeability transfer constant, K(trans), derived by a pharmacokinetic modeling algorithm, were also obtained. These results were compared with rCBV and K(trans) values obtained in a group of low grade gliomas (n = 30) and a group of high grade gliomas (n = 55) by using a Student t test. RESULTS: On conventional MR images, PNETs were generally well-defined contrast-enhancing masses with solid and cystic components, little or no surrounding edema, and occasional regions of susceptibility. The rCBV of cerebral PNETs was 4.76 +/- 1.99 SD, and the K(trans) was 0.0033 +/- 0.0035. A comparative group of patients with low grade gliomas (n = 30) had significantly lower rCBV (P <.0005) and lower K(trans) (P <.05). Comparison with a group of high grade gliomas showed no statistical significance in the rCBV and K(trans) (P =.53 and.19, respectively). CONCLUSION: Dynamic, susceptibility-weighted, contrast-enhanced MR imaging shows areas of increased cerebral blood volume and vascular permeability in PNETs. These results may be helpful in the diagnosis and preoperative differentiation between PNETs and other intracranial mass lesions (such as low grade gliomas), which have decreased perfusion but may sometimes have a similar conventional MR imaging appearance.

Adult↗
PubMed1996

Neurotrophin and neurotrophin receptor proteins in medulloblastomas and other primitive neuroectodermal tumors of the pediatric central nervous system.

Primitive neuroectodermal tumors (PNETs) of the central nervous system (CNS) are poorly understood childhood neoplasms, and medulloblastomas are the most common pediatric PNETs. Neoplastic cells in medulloblastomas and other PNETs resemble progenitor cells of the developing central nervous system, but they also may exhibit the molecular phenotype of immature neurons or glia. As neurotrophins play a role in regulating differentiation, proliferation, and cell death in the normal developing central nervous system, and recent evidence suggests that neurotrophins may influence the behavior of medulloblastomas, we studied 29 PNET biopsy samples (27 of which were posterior fossa medulloblastomas) by immunobistochemistry using antibodies specific for each of the major high affinity neurotrophin receptor proteins, ie, TrkA, TrkB, and TrkC. A subset of these tumors also was examined by Western blot. Immunoreactive TrkA, TrkB, and TrkC were observed in neoplastic cells in 8 (27%), 18 (62%), and 14 (48%) of these PNETs, respectively. Additional immunohistochemical studies of a subset of these PNETs using antibodies to neurotrophins that primarily activate TrkB and TrkC, ie, brain-derived neurotrophic factor, neurotrophin-3, and neurotrophin-4/5, showed that immunoreactive brain-derived neurotrophic factor, neurotrophin-3, and neurotrophin-4/5 were detected in 22, 9, and 19% of these PNET biopsies, respectively. Finally, 19 pediatric brain tumors other than these PNETs also were studied here, and they expressed these neurotrophins and their receptors to a variable extent. The demonstration here that neurotrophins and their cognate receptor proteins are expressed in PNETs as well as in other pediatric brain tumors may imply that signal transduction pathways mediated by neurotrophins and/or their receptors influence the induction or progression of these common childhood neoplasms.

Adolescent↗
PubMed1997

Mutations in the human homologue of the Drosophila segment polarity gene patched (PTCH) in sporadic basal cell carcinomas of the skin and primitive neuroectodermal tumors of the central nervous system.

The human homologue of the Drosophila segment polarity gene patched (PTCH) has recently been identified as the tumor suppressor gene responsible for the nevoid basal cell carcinoma (BCC) syndrome (H. Hahn et al., Cell, 85: 841-851, 1996; R. L. Johnson et al., Science (Washington DC), 272: 1668-1671, 1996). In addition to multiple BCCs, patients with nevoid BCC syndrome have a predisposition for the development of primitive neuroectodermal tumors (PNETs) of the central nervous system. We have analyzed 9 sporadic BCCs and 37 PNETs for mutation and expression of the PTCH gene. PTCH mutations were found in 3 BCCs (33.3%) and in 5 PNETs (14%), including 1 of 5 cerebral PNETs, 2 of 15 medulloblastomas, and 2 of 17 desmoplastic medulloblastomas. The sequence changes in six of these tumors (four PNETs, two BCCs) were mutations predicted to result in truncated proteins. Missense mutations were detected in one PNET and one BCC each. In addition, novel sequence polymorphisms were found in exon 2, intron 5, intron 10, and intron 14 of PTCH. Reverse transcription-PCR analysis revealed increased PTCH expression levels compared to nonneoplastic brain tissue and normal skin in the majority of PNETs and BCCs investigated. Our data suggest that genetic alterations of PTCH are not only of significance in hereditary and sporadic BCCs but are also involved in the molecular pathogenesis of a subset of sporadic central nervous system PNETs.

Adolescent↗
PubMed2000

Are clinical parameters valuable prognostic factors in childhood primitive neuroectodermal tumors? A multivariate analysis of 105 cases.

BACKGROUND: Medulloblastoma is one of the most frequent brain tumors in children. Long-term survivors are often confronted with serious late sequelae, caused by the therapy. Therefore, prognostic markers must be identified that allow the children to be assigned to different treatment schedules according to their predicted outcome. PATIENTS AND METHODS: The medical data of 110 children with a medulloblastoma or central primitive neuroectodermal tumor (PNET), that were admitted to the Emma Kinderziekenhuis in Amsterdam were analyzed by univariate and multivariate analyses. RESULTS: In univariate analysis the following characteristics had a significant influence on progression free survival (PFS): (a) presence of meningeal metastases at the time of diagnosis, (b) presence of tumor cells in the cerebrospinal fluid before or after surgery, (c) extent of resection, (d) necessity for permanent cerebrospinal fluid (CSF) shunting and (e) radiation dose to the posterior fossa. On multivariate analysis only the presence of metastases and the radiation dose to the posterior fossa retained significance. CONCLUSION: At the time of diagnosis, no reliable clinical prognostic markers are available for the majority of patients. Further molecular studies must be undertaken to identify such prognostic factors.

Adolescent↗