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PubMed2004

Primitive neuroectodermal kidney tumour.

Renal primitive neuroectodermal tumour (PNET) is a rare malignant tumour of paediatric patients. We describe the important imaging findings, including the ultrasound, CT and MRI of a case of renal PNET in a teenager. To our knowledge, some findings have not been described previously. Some features that have been considered as characteristic are not present in our case, and it is, to our knowledge, the first documented case with such extensive tumour thrombus. We also demonstrate the importance of including PNET as a differential diagnosis because combined chemotherapy is thought to be the best first-line treatment in most cases. Histological diagnosis can be determined by a minimally invasive procedure instead of laparotomy or open biopsy.

Adolescent↗

PubMed2004

PNET of the hallux.

We present the case of a 21-year-old lady who presented with a peripheral primitive neuroectodermal tumour (pPNET) of the distal phalanx of the right great toe. She had an amputation through her metatarso-phalangeal joint, the diagnosis having been confirmed histologically. Although her resection margins were clear and radiological staging revealed no metastases, she was commenced on adjuvant chemotherapy due to the high rate of metastases associated with the disease. Her surgery came after two years of intermittent pain and swelling of her toe, during which time she was undergoing conservative management, with serial visits to the outpatients department, of a radiological (magnetic resonance imaging) diagnosis of a haemangioma. This case report details her background, diagnosis and treatment as well as presenting a literature review of what is an unusual tumour in a previously unreported site.

Adult↗

PubMed1989

Ultrastructural morphometry distinguishes Burkitt's-like lymphomas from neuroendocrine neoplasms: useful criteria applied to the evaluation of a poorly differentiated neuroendocrine neoplasm of the nasal cavity masquerading as Burkitt's-like lymphoma.

The present study describes the potential usefulness of ultrastructural morphometry in diagnosis. Ultrastructural morphometric criteria were applied to the evaluation of a poorly differentiated neuroendocrine neoplasm of the nasal cavity that was initially thought to be a Burkitt's-like lymphoma (BLL). Although the nasal lesion in question failed to stain with over 50 cell lineage-relevant antibodies, it did stain for vimentin (an intermediate filament protein) and Ki-67 (a nuclear antigen associated with cell proliferation). Routine electron microscopy revealed a primitive neoplasm with abundant cytoplasmic lipid droplets and sparse dense granules with no intercellular junctions. Treatment options, which included extensive facial surgery, prompted more study. Tissue processed for the uranaffin reaction revealed sparse uranaffin-positive granules indicating the presence of true neurosecretory granules. An ultrastructural morphometric analysis of the neoplastic nuclei of this patient placed the tumor outside the morphometric domains for BLLs (18 cases) and neuroblastomas (11 cases) and within the morphometric domain of neuroendocrine carcinomas (9 cases). A greater mean standard deviation (P less than 0.05) and mean coefficient of variation (P less than 0.02) of nuclear perimeter in the neuroendocrine (NE) group related to the BLL group indicated greater nuclear pleomorphism within the NE group as illustrated in bivariate graphic displays. The possible origin of the neoplasm within the nasal mucosa is discussed.

Burkitt Lymphoma↗

PubMed1990

Ultrastructural pleomorphism in medulloepithelioma of the ciliary body: a comparative study of tumour cells and fetal ciliary epithelium.

A locally aggressive nonteratoid intraocular medulloepithelioma occurring in a two-year-old boy was studied by electron microscopy. For comparison the primitive pars plana region was examined in human fetal eyes obtained at 16, 18 and 22 weeks of gestation. The tumour was polymorphic with neural, intermediate and epithelial components. The neural component of the tumour resembled the zonulae adherentes dominant cell junction seen in the apical part of the unpigmented epithelium at 16 weeks, while the well-developed junctional complexes and interdigitations seen in the unpigmented epithelium at 22 weeks resembled those in the epithelial component of the tumour. Intermediate cells which exhibited characteristics of both neural and epithelial components, particularly in the cell junctional features, were found. Pleomorphism in nonteratoid medulloepithelioma might be accounted for by the developmental stage at which the tumour is initiated.

Ciliary Body↗

PubMed2002

Peripheral primitive neuroectodermal tumour during pregnancy.

The case of a 25-year-old primipara in the second trimester of pregnancy, suffering from a peripheral primitive neuroectodermal tumour (pPNET) diagnosed by bone biopsy, is described. External irradiation was initially performed because of Jacksonian seizures due to a lesion in the right cerebral hemisphere. Appropriate shielding was used to reduce fetal exposure during brain radiotherapy. Caesarian delivery at the 27th week of gestation was performed because of tumour progression. The neonate had no evidence of disease and survived for 1 month. However, the placenta and ovaries showed metastases from the maternal pPNET. The patient died 14 months after initial diagnosis owing to the aggressiveness of the tumour, the rapid and extensive semination (bone marrow, lung, liver, craniospinal axis involvement) and the inability to adequately treat the patient with appropriate doses of chemotherapy.

Adult↗

PubMed1992

Two malignant peripheral primitive neuroepithelial tumor cell lines established from consecutive samples of one patient: characterization and cytogenetic analysis.

A 6-year-old girl presented with a tumor of the right shoulder involving bone, adjacent soft tissue, and regional lymph nodes. The conventional histologic diagnosis was ambiguous, initially suggesting lymphoma. After relapse on lymphoma therapy, reevaluation with additional multiple diagnostic techniques performed on the biopsy tissue and on two cell lines derived from the biopsies established the diagnosis of a primitive neuroepithelial tumor of bone and soft tissue. This was strongly supported by 1) focal rosette formation by the tumor cells and positive immunostaining for neuron-specific enolase and synaptophysin, with absent staining for leukocyte common antigen; 2) at the ultrastructural level, formation of cellular processes containing microtubules, a paucity of neurosecretory granules, absence of synaptic junctions, formation of long "intermediate" junctions between cells, and, in culture, widespread development of rosettes; 3) marked surface positivity to W 6/32 and negativity to HSAN 1.2 antibodies; and 4) elevated expression of MYC and lack of overexpression of MYCN oncogenes. Numerical and structural abnormalities were present in the karyotype, but the expected t(11;22)(q24;q12) was not present in the tumor-involved marrow or in either of the established tumor cell lines, although there was an interstitial deletion of 11q involving breakpoints in q21 and q23.

Biomarkers, Tumor↗

PubMed1991

Basic fibroblast growth factor and somatomedin C in human medulloepithelioma.

Two published cases of medulloepithelioma, a rare malignant pediatric brain tumor composed of a mixture of primitive neuroepithelium and its differentiated neuronal and glial descendants, were examined by immunohistochemical staining for the presence of growth factors. From a panel of antibodies, those identifying basic fibroblast growth factor and insulin-like growth factor I, formerly known as somatomedin C, were strongly immunoreactive within the neuroepithelial cell population of the tumors. Immunoblots of purified recombinant basic fibroblast growth factor and insulin-like growth factor I showed antibody specificity without cross-reactivity. In controls, immunostaining of tissue sections was abolished by preabsorption of primary antibodies with the appropriate growth factor polypeptide antigen. Preabsorption with inappropriate growth factor did not reduce the intensity or alter the distribution of staining. The congruent histologic patterns of immunoreactivities suggest that more than one type of growth factor may be produced by the neuroepithelial component of medulloepithelioma. These growth factors may stimulate proliferation and differentiation of tumor cells by autocrine molecular mechanisms.

Animals↗

PubMed2004

First spinal axis segment irradiation with spot-scanning proton beam delivered in the treatment of a lumbar primitive neuroectodermal tumour. Case report and review of the literature.

Primary intraspinal primitive neuroectodermal tumour (PNET) is a rare tumour entity. The optimal therapeutic management is unclear but, in general, this tumour is treated with surgery followed by radiotherapy and chemotherapy. Proton beam radiation therapy (PT) offers superior dose distributional qualities compared with X- or gamma rays, as the dose deposition occurs in a modulated narrow zone called the Bragg peak. As a result, organs at risk are optimally speared. Here, we present a patient treated with the first spinal axis segment irradiation using spot-scanning PT with a single field, combined with conventional cranio-spinal axis radiotherapy after surgery and chemotherapy, and an extensive review of the literature outlining the clinical features and treatment modality of spinal PNET.

Adult↗

PubMed2004

No evidence for mutations or altered expression of the Suppressor of Fused gene (SUFU) in primitive neuroectodermal tumours.

The sonic hedgehog (Shh) and the Wnt signalling pathways are involved in the development of medulloblastomas (MBs), the most frequent malignant brain tumours in children. Components of these two developmental and cancer-associated pathways, including (Patched) PTCH, SMOH, adenomatous polyposis coli (APC), beta-catenin and AXIN1 show somatic mutations in sporadic MBs. In this study we analysed SUFU (human Suppressor of Fused), which acts as a negative regulator of both the Shh and Wnt signalling pathways and therefore represents a putative tumour suppressor gene, to find out if it is also involved in the pathogenesis of sporadic MBs. We screened 145 primitive neuroectodermal tumours (PNETs) including 90 classic MBs, 42 of the desmoplastic variant and two medullomyoblastomas as well as 11 MB cell lines for mutations using single-strand conformational polymorphism (SSCP) and sequencing analysis. 18% of the MBs exhibited allelic losses on chromosome 10q. In contrast to a previous report, in which truncating mutations of SUFU have been identified in 9% of MBs, we were not able to identify somatic mutations of SUFU in our large tumour panel. We uncovered single nucleotide polymorphisms (SNPs) in exon 4, 8, 11 and in intron 2 in the SUFU gene. Expression analysis by competitive reverse transcription-polymerase chain reaction (RT-PCR) revealed no difference in SUFU mRNA levels of both MB subtypes and normal foetal or adult cerebellar tissues. Our results indicate that genetic alterations of the SUFU gene, do not contribute significantly to the molecular pathogenesis of MBs.

Adolescent↗

PubMed1994

Differential expression of beta 1, beta 3, and beta 4 integrin subunits in nonneoplastic neural cells of the peripheral and autonomic nervous system and in tumors derived from these cells.

BACKGROUND: Extracellular matrix proteins and their receptors take part in physiologic neural development and organization and also in abnormal neoplastic growth and spread. There is increasing evidence for the implication of integrins in these processes. EXPERIMENTAL DESIGN: Human tissues containing nonneoplastic neural cells of the peripheral and autonomic nervous system and a comprehensive series of neural tumors were examined for the in situ expression of beta 1, beta 3, and beta 4 integrins. Serial frozen sections of each tissue sample were immunostained using an indirect streptavidin/biotin-peroxidase method and monoclonal antibodies against beta 1, alpha 1 to alpha 6, beta 3, alpha v, and beta 4 subunits. RESULTS: Both small- and large-diameter nerve fibers of normal peripheral nerve trunks were consistently beta 1+, alpha 6+, and beta 4+ in the absence of alpha 3, alpha 4, alpha 5, and beta 3. Small-diameter nerve fibers further expressed alpha 1, alpha 2, and alpha v. Meissner's corpuscles and inner cores of Pacinian corpuscles shared the integrin repertoire of small-diameter nerve fibers with additional expression of alpha 3; outer cores of Pacinian corpuscles were beta 1+, alpha 3+, alpha 6+, and beta 4+. Regenerating nerve fibers paralleled the integrin profile of normal peripheral nerves. By contrast, malignant schwannomas showed considerable changes in integrin expression. These alterations consisted mainly in a neoexpression of alpha 3, alpha 4, and alpha 5 and in an abnormal loss of alpha 6 and beta 4. Expression of alpha 1, alpha 2, and alpha v was variable; absence of beta 3 was generally conserved. In ganglion cells, integrin expression was restricted to beta 1 and alpha 3 subunits, and chromaffine cells of the adrenal medulla even lacked any detectable beta 1, beta 3, and beta 4 integrin subunits. (Ganglio)-neuroblastomas, however, were beta 1+, alpha 1+, and alpha 3+, whereas primitive peripheral neuroectodermal tumors were beta 1+ and alpha 5+. CONCLUSIONS: Nonneoplastic human neural cells exhibit a complex and, at the same time, differential pattern of beta 1, beta 3, and beta 4 integrin subunit expression. Malignant transformation leads to considerable changes in this integrin profile. The observation of neoplasia-associated abnormalities underlines the important role of integrins in the orderly development and maintenance of human neural tissue. Some aspects of the emerging integrin subunit patterns are useful for the differential diagnosis of neural soft-tissue tumors.

Adrenal Glands↗

PubMed2004

Fibroblast growth factor 2 induces differentiation and apoptosis of Askin tumour cells.

Peripheral primitive neuroectodermal tumour (PNET)/Ewing's sarcoma (ES) and neuroblastoma (NB) are related tumours of neural crest origin with primitive neural characteristics. Fibroblast growth factor 2 (FGF2) is a critical signalling molecule for primitive neural crest cells. The treatment of NB cells with FGF2 variably affects biological characteristics such as growth and differentiation, while in PNET/ES, FGF2 predominantly induces apoptosis. The JK-GMS Askin tumour cell line can be induced to differentiate upon treatment with nerve growth factor (NGF), indicating the integrity of the cellular machinery necessary for differentiation. The present study assesses whether FGF2 can induce differentiation in JK-GMS cells. JK-GMS cells expressed high-affinity FGF receptors (FGFRs), and treatment with FGF2 induced phosphorylation of FGFR1 together with activation of extracellular signal-regulated kinases (ERK1/ERK2) and c-Jun N-terminal kinase (JNK). Subsequent biological effects were growth inhibition, neuronal differentiation, and apoptosis, and these changes were associated with increased expression of neurofilaments, reduction of c-myc and bcl-2 expression, and activation of caspase 3. Treatment of the cells with a specific inhibitor of the MAPK/extracellular signal-regulated kinase (MEK)-1, PD98059, predominantly inhibited the effects of FGF2 on growth, differentiation, and apoptosis, while an inhibitor of JNK reduced apoptosis, indicating that the ERK1/2 and JNK pathways are critical components of FGF2-mediated effects in JK-GMS cells. Additional comparative analyses of FGF2-mediated effects in two ES cell lines (CADO-ES, RD-ES) and a PNET cell line (SK-N-MC) showed pronounced differentiation in SK-N-MC, but not in CADO-ES or RD-ES cells. This study demonstrates that FGF2 can induce neuronal differentiation of PNET including Askin tumour. These findings clearly indicate that the FGF2-mediated signalling pathway plays a critical role in controlling the major properties of PNET cells and may provide a potential therapeutic target for PNET.

Apoptosis↗

PubMed2001

Malignant teratoma of the thyroid with primitive neuroepithelial and mesenchymal sarcomatous components.

A 15-year-old black girl had a near total resection of a malignant thyroid teratoma with bilateral nodal involvement and mediastinal extension. A predominant neuroepithelial pattern had ependymal rosettes and mitoses, stained for neuron-specific enolase, neuron-specific B tubulin, and synaptophysin. A malignant spindle cell component stained for smooth-muscle actin, muscle actin, and to a lesser extent S-100. Loose myxoid tissue resembled primitive cartilage. Epithelial membrane antigen and cytokeratin identified epithelial foci. Chromogranin A, MIC2, glial fibrillary acidic protein, and thyroid stimulating hormone receptor stains were negative. There was focal anaplasia. DNA ploidy by laser scanning cytometry was 1.2. The tumor from the left and right thyroid lobes exhibited trisomy 8, the right also had hyperdiploid cell lines. She was treated with aggressive combination chemotherapy and radiation. Presently there is no residual disease 16 months after diagnosis. Malignant thyroid teratoma is an aggressive tumor, with 15 of 27 reported patients dying 2 weeks to 3 years after diagnosis. Survivors have been treated with total or subtotal resection, combination chemotherapy with agents effective in the treatment of germ cell tumors as well as sarcomas, and radiation for either recurrent or residual disease. The heterologous elements, lacking MIC2 staining and t(11;22), support the diagnosis of malignant teratoma rather than a neuroepithelial tumor. Trisomy 8 is the first cytogenetic abnormality described in malignant thyroid teratoma. Therapy should be tailored to the management of all transformed histologies.

Adolescent↗

PubMed2001

Angiogenic profile of childhood primitive neuroectodermal brain tumours/medulloblastomas.

Primitive neuroectodermal brain tumours (PNET) including medulloblastomas (PNET/MB) are the most common malignant brain tumours of childhood. Similar to many other brain tumours, PNET/MB often show marked neovascularisation. To determine which angiogenic factors contribute to PNET/MB angiogenesis, we examined the expression of eight angiogenic factors (vascular endothelial growth factors (VEGF, VEGF-B, VEGF-C), basic fibroblast growth factor (bFGF), angiopoetins (Ang-1, Ang-2), transforming growth factor (TGF-alpha), and platelet-derived endothelial growth factor (PDGF-A)) by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) in six PNET cell lines and 28 primary PNET/MB. Expression levels of angiogenic factors were compared with microvessel density, TrkC mRNA expression, clinical variables and survival outcomes. Our results indicate that all PNET/MB tested produce a wide range of angiogenic factors that are, individually or together, likely to play a direct role in PNET/MB tumour growth. This suggests that anti-angiogenesis approaches targeting VEGF alone may be insufficient in PNET/MB.

Adolescent↗

PubMed1999

Comparative genomic hybridization detects many recurrent imbalances in central nervous system primitive neuroectodermal tumours in children.

A series of 23 children with primitive neuroectodermal tumours (PNET) were analysed with comparative genomic hybridization (CGH). Multiple chromosomal imbalances have been detected in 20 patients. The most frequently involved chromosome was chromosome 17, with a gain of 17q (11 cases) and loss of 17p (eight cases). Further recurrent copy number changes were detected. Extra copies of chromosome 7 were present in nine patients and gains of 1q were detected in six patients. A moderate genomic amplification was detected in one patient, involving two sites on 3p and the whole 12p. Losses were more frequent, and especially involved the chromosomes 11 (nine cases), 10q (eight cases), 8 (six cases), X (six patients) and 3 (five cases), and part of chromosome 9 (five cases). These recurrent chromosomal changes may highlight locations of novel genes with an important role in the development and/or progression of PNET.

Adolescent↗

PubMed1998

Contrasting levels of p21ras activation and expression of neurofibromin in peripheral primitive neuroectodermal tumour and neuroblastoma cells, and their response to retinoic acid.

Ras protooncogenes encode small guanine nucleotide binding proteins (p21ras) activated by phosphorylation. Phosphorylation of p21ras is predominantly regulated by the GTPase activating proteins type 1 GAP120 and neurofibromin. Increased levels of p21ras-GTP (active) have been associated with increased cell growth and malignant transformation. In this study the relationship between p21ras, type 1 GAP120 and neurofibromin with growth and differentiation has been examined in neuroblastoma and peripheral primitive neuroectodermal tumour (pPNET) cell lines. The level of p21ras protein in neuroblastoma and pPNET cells was the same. However, the amount of p21ras-GTP bound was higher in pPNET than in neuroblastoma cells. This most likely reflects the absence of neurofibromin. Retinoic acid (RA)-induced differentiation and growth inhibition of neuroblastoma cells was associated with an increase in type 1 GAP120 and neurofibromin mRNA, and a decrease in p21ras-GTP. In pPNET cells levels of type 1 GAP120 but not neurofibromin mRNA were increased to similar levels to those in neuroblastoma cells. This was not associated with decreased p21ras-GTP, modulation of growth or change in morphology. In summary, constitutive activation of p21ras may have a role in the biology of pPNET cells. This may reflect abnormalities in neurofibromin expression, and could inpart explain why RA did not induce morphological differentiation and growth inhibition in pPNETs.

Cell Differentiation↗

PubMed1994

Combination chemotherapy for primitive neuroectodermal and other malignant brain tumours.

The toxicity and efficacy of a chemotherapy schedule comprising vincristine and cyclophosphamide, alternating with carboplatin and etoposide, has been assessed in a group of 15 patients with medulloblastoma, supratentorial primitive neuroectodermal tumours (PNET) or other malignant brain tumours. The patients comprised four adults and 11 children. Chemotherapy was given for palliation of recurrent disease (six patients), as an adjuvant to radiotherapy and surgery in five poor prognosis patients, or to delay the need for radiotherapy in four children aged 2 years or less. The treatment was generally well tolerated, with the principal toxicity being myelo-suppression. Among the ten assessable patients, there were six complete responders and one partial, an overall response rate of 70%. Three patients had progressive disease. Responses, although associated with good symptomatic improvement, were short lived, with two patients relapsing while still receiving chemotherapy. Three of four very young children relapsed within 7 months of completing chemotherapy and then received radiotherapy. It is concluded that this schedule merits further evaluation and comparison with more protracted and toxic schedules.

Adolescent↗

PubMed1997

Metabolic studies of human primitive neuroectodermal tumour cells by proton nuclear magnetic resonance spectroscopy.

Well-characterized cell lines established from primitive neuroectodermal tumours (PNETs) were examined by proton nuclear magnetic resonance (1H-NMR) spectroscopy and chromatographic analysis of perchloric acid extracts, following amplification in cell culture. A characteristic 1H-NMR spectroscopic metabolite pattern was found for medulloblastoma cell lines, which clearly discriminates these cells from PNETs of other locations in the central nervous system (CNS), on the basis of their N-acetyl aspartate (NAA) and aspartate expression. Medulloblastoma cell lines were heterogeneous in respect of their metabolite expression, possibly owing to the heterogeneity in their differentiation along lineages of the CNS. All PNET spectra displayed similar features, including decreased NAA and creatine peaks and increased signals from choline compounds (Cho) compared with normal cerebellum. The expression of NAA by the medulloblastoma lines was in the opposite order to the extent of neuronal differentiation, which may indicate their origin from a progenitor cell with the phenotype of an oligodendrocyte-type-2 astrocyte cell.

Aspartic Acid↗

PubMed2006

Primary primitive neuroectodermal tumour of the urinary bladder: a clinico-pathological study emphasising immunohistochemical, ultrastructural and molecular analyses.

Primary primitive neuroectodermal tumours (PNETs) of the bladder are extremely rare and aggressive neoplasms, and only six examples have been reported in the literature. The case of a 21-year-old woman, who remains disease free 3 years after tumour resection, is reported here. Morphological features were found to correspond to a small round blue cell tumour without rosette formation and with extensive areas of necrosis. Strong expression of CD99, vimentin and CD117 (c-kit), and focal reactivity to cytokeratin and S-100 protein was observed in tumour cells. Ultrastructurally, sparse neurosecretory granules were observed. Diagnosis of PNET was supported by molecular genetic analysis, showing the EWS-FLI-1 fusion transcript type 2 by RT-PCR and EWS gene rearrangement by fluorescence in situ hybridisation. A normal genetically balanced genotype was shown by comparative genomic hybridisation, which, together with the expression of c-kit, a known therapeutic target for imatinib, may have prognostic and therapeutic implications.

Adult↗