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PubMed1998

Molecular diagnosis of Ewing tumors: improved detection of EWS-FLI-1 and EWS-ERG chimeric transcripts and rapid determination of exon combinations.

Most Ewing tumors (ET), including Ewing sarcomas, peripheral primitive neuroectodermal tumors (PNET), and Askin's tumors, can be defined according to the specific chromosomal translocations t(11;22)(q24;q12) (EWS-FLI-1) or t(21;22)(q21;q12) (EWS-ERG). Detection of the chimeric RNA transcripts by reverse transcriptase-polymerase chain reaction (RT-PCR) has greatly facilitated the diagnosis of ET. Because of variable chromosomal breakpoint locations, however, the EWS gene fusions with FLI-1 and ERG genes are highly heterogenous, resulting in different sizes of the amplification products. To improve the diagnostic usefulness of the RT-PCR assay, we have developed an assay to detect chimeric mRNA transcripts by nested RT-PCR, followed by digestion of the PCR fragments with three different restriction endonucleases. This allows confirmation of the specificity of the PCR product and provides a rapid method to determine the combination of exons present in a transcript. In the 12 Ewing tumors tested, five different exon combinations were detected. In nine repeat biopsies of four patients, the case-specific translocation remained unchanged. One additional central PNET had no ET-specific translocation. In conclusion, the suggested combination of RT-PCR and restriction analysis of the PCR products allows a rapid and specific determination of ET-specific translocations.

Adolescent↗
PubMed1988

Pathology, treatment and management of posterior fossa brain tumors in childhood.

Brain tumors are the second most common childhood malignancy. Between 1975 and 1985, 462 newly diagnosed patients were treated at the Children's Hospital of Philadelphia; 207 (45%) tumors arose in the posterior fossa and 255 (55%) appeared supratentorially. A wide variety of histological subtypes were seen, each requiring tumor-specific treatment approaches. These included primitive neuroectodermal tumor (n = 86, 19%), astrocytoma (n = 135, 30%), brainstem glioma (n = 47, 10%), anaplastic astrocytoma (n = 32, 7%), and ependymoma (n = 30, 6%). Because of advances in diagnostic abilities, surgery, radiotherapy, and chemotherapy, between 60% and 70% of these patients are alive today. Diagnostic tools such as computed tomography and magnetic resonance imaging allow for better perioperative management and follow-up, while the operating microscope, CO2 laser, cavitron ultrasonic aspirator and neurosurgical microinstrumentation allow for more extensive and safer surgery. Disease specific treatment protocols, utilizing radiotherapy and adjuvant chemotherapy, have made survival common in tumors such as medulloblastoma. As survival rates increase, cognitive, endocrinologic and psychologic sequelae become increasingly important. The optimal management of children with brain tumors demands a multidisciplinary approach, best facilitated by a neuro-oncology team composed of multiple subspecialists. This article addresses incidence, classification and histology, clinical presentation, diagnosis, pre-, intra- and postoperative management, long-term effects and the team approach in posterior fossa tumors in childhood. Management of specific tumor types is included as well.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1979

Brain tumors in childhood.

A review of the pathology of 689 neuroectodermal tumors occurring over a 30-year period at The Hospital for Sick Children in Toronto has underlined the importance of examining the tissue from each tumor in order to insure consistency and accuracy in histological diagnosis. The age, sex, histology and topographical distribution of this series of tumors is compared with other series and discussed in detail. The high proportion of tumors occurring in early childhood, the striking male preponderance, and the high incidence of astrocytomas, medulloblastomas and ependymomas is emphasized.

Adolescent↗
PubMed1992

Magnetic resonance imaging of pediatric posterior fossa tumors.

MR detected abnormality in all 115 pediatric patients who subsequently had pathologically proven posterior fossa tumors. In 114, the initial magnetic resonance (MR) diagnosis was that of brain tumor. In 1, with less than 1-cm2 area of gadolinium enhancement, the significance of the initial finding was uncertain. Common posterior fossa tumor subgroups (brainstem gliomas, cerebellar astrocytomas, primitive neuroectodermal tumors, and ependymomas) have relatively consistent presentations on imaging studies. However, less common tumors mimic the MR appearance of more common ones, while common tumors may also have atypical appearances.

Adolescent↗
PubMed1993

Human neuroblastoma cells express alpha and beta platelet-derived growth factor receptors coupling with neurotrophic and chemotactic signaling.

Both platelet-derived growth factor (PDGF) A- and B-chains are expressed in mammalian neurons, but their precise roles still remain to be clarified. In the present studies, we examined the expression of two PDGF receptor genes in human tumor cell lines derived from neural crest. The expression of alpha and/or beta PDGF receptors was detected in a wide variety of neural crest-derived human tumor cell lines such as neuroblastoma, primitive neuroectodermal tumor, and Ewing's sarcoma by RNA blot analysis, and confirmed by immunoblot analysis. We have also demonstrated that PDGF receptors on the human neuroblastoma cell lines were biologically functional. Accordingly, chemotactic and mitogenic activities were induced by either PDGF-AA or PDGF-BB in serum-free medium. PDGF isoforms as well as nerve growth factor induced morphological changes showing neuronal cell maturation. Moreover, PDGF coordinately increased the levels of the transcript of the midsize neurofilament gene. The neuroblastoma cell lines also expressed the transcripts of PDGF A- and B-chains. These findings suggest that PDGF isoforms are involved not only in the promotion of the neuroblastoma cell growth, but also in neuronal cell migration, growth, and differentiation in human brain development.

Amino Acid Sequence↗
PubMed1999

Clinicopathological characteristics of atypical teratoid/rhabdoid tumor.

The clinicopathological features of atypical teratoid/rhabdoid tumor, a new entity among malignant pediatric brain tumors, and the differential diagnosis from primitive neuroectodermal tumor (PNET)/medulloblastoma, and germ cell tumor are described. Histologically, atypical teratoid/rhabdoid tumor is defined as a polymorphous neoplasm often featuring rhabdoid, PNET, epithelial, and mesenchymal components. Atypical teratoid/rhabdoid tumors usually include PNET components and occur mainly in the posterior fossa, so mimic medulloblastoma. Atypical teratoid/rhabdoid tumor is characterized by the cytogenetic finding of monosomy 22 rather than i(17q). The tumor is similarly mistaken for PNET at supratentorial sites. Germ cell tumors also enter into the differential diagnosis due to their histological immunophenotypic diversity, particularly features indicative of epithelial and mesenchymal differentiation. Nonetheless, the remarkable spectrum of tissues that typify teratoma is absent in atypical teratoid/rhabdoid tumor. The same is true of germ cell marker in tumor tissues and serum. The prognosis of atypical teratoid/rhabdoid tumor is far less favorable than that of PNET/medulloblastoma of malignant or germ cell tumor. Meta-analysis of 133 cases, including 15 new and 118 reported cases, confirm that atypical teratoid/rhabdoid tumor is as a clinicopathological entity and emphasizes the necessity for distinguishing this unique tumor from other pediatric central nervous system neoplasms.

Adolescent↗
PubMed1996

Central nervous system atypical teratoid/rhabdoid tumors of infancy and childhood: definition of an entity.

Clinical and pathological features of 52 infants and children with atypical teratoid/rhabdoid tumor (ATT/RhT) of the central nervous system are defined. This tumor is typically misdiagnosed as a primitive neuroectodermal tumor (PNET) primarily because 70% of ATT/RhTs contain fields indistinguishable from classic PNETs. Separation of these two tumor types is crucial because the prognosis for ATT/RhT is given even when treatment includes surgery with or without radio and/or chemotherapy. These tumors are most common in infants less than 2 years of age. The cases described in this study arose in intracranially in all but one instance, although one-third had already spread throughout the subarachnoid space at presentation. Clinical signs and symptoms and radiological features do not distinguish ATT/RhTs from PNETs. The tumors are composed entirely (13%) or partly (77%) or rhabdoid cells. Seventy percent contains fields of typical PNET alone or in combinations with mesenchymal and/r epithelial elements. The immunohistochemical profile is unique: epithelial membrane antigen, vimentin, and smooth-muscle actin are positive in the majority of tumors and markers for germ-cell tumors are consistently negative. Abnormalities of chromosome 22 distinguish ATT/RhTs from PNETs, which typically display an i(17q) abnormality.

Antibodies↗
PubMed2000

Efficacy of neuroendoscopic procedures in minimally invasive preferential management of pineal region tumors: a prospective study.

OBJECT: This prospective study is based on a consecutive series of 20 patients with pineal region tumors who underwent minimally invasive preferential management. The purpose of this report is to discuss the role of neuroendoscopic procedures in the management of pineal region tumors. METHODS: If the tumor markers alpha-fetoprotein and human chorionic gonadotropin were not detected in serum and there was significant ventricular dilation visualized on neuroimages, neuroendoscopic surgery was first applied for tumor debulking with tissue diagnosis and gross morphological analysis of the tumor and the intraventricular structures, followed by third ventriculostomy. Subsequent procedures were determined on the basis of verified individual tumors. For treatment of germinomas and pineoblastomas, if no tumor dissemination was confirmed by pre-, intra-, or postoperative findings, stereotactic radiotherapy or radiosurgery was performed after one course of chemotherapy with the ICE regimen (isofomid, cisplatin, and etoposide) and followed by two additional courses of chemotherapy. For treatment of malignant germ cell tumors, after extensive surgery, adjuvant chemotherapy with the ICE regimen was performed in three courses in all cases. Then radiotherapy was started using various methods, depending on the evidence of tumor dissemination. For treatment of teratomatous and neuroectodermal tumors other than pineoblastomas, extensive surgical removal was performed. As for adjuvant therapy, if the tumor was a low-grade glioma or if the patient was younger than 5 years of age, postoperative treatment did not include radiotherapy. If the tumor was a malignant teratoma or high-grade glioma, conventional focal radiotherapy was performed, followed by chemotherapy with ICE for 1 year. All but two treated patients had ventriculomegaly. Neuroendoscopic procedures were performed in six of 15 treated patients. Neuroendoscopic biopsy with tumor debulking offered enough material for tissue diagnosis, including immunohistochemical analysis and, in one case, revealed evidence of tumor dissemination undetectable on neuroimaging. With one exception, no shunt was required in any patient undergoing endoscopic third ventriculostomy. Stereotactic radiotherapy was performed in indicated cases. Favorable therapeutic outcomes were obtained in all cases of germinoma and pineoblastoma, with follow-up periods ranging from 24 months to 6.5 years. CONCLUSIONS: Our minimally invasive preferential regimen clarified the precise indication for neuroendoscopic procedures, and the majority of our patients with dilated ventricles and no evidence of tumor markers were treated satisfactorily with effective neuroendoscopic procedures as the initial procedure, avoiding unnecessary craniotomy and radiotherapy and promising excellent therapeutic outcomes. The treatment for malignant pineal region tumors remains a subject for further study.

Adolescent↗
PubMed1992

[Analysis of surface membrane antigens, cytoskeletal proteins and N-myc oncogene in pediatric solid malignant tumors, their diagnostic usefulness and relevant problems].

Neuroblastoma (NB), primitive neuroectodermal tumor (PNET), Ewing's sarcoma and rhabdomyosarcoma (RMS) are solid malignant tumors in childhood. Microscopically these tumors are grouped as small-round-cell tumors, and a different diagnosis is sometimes difficult. Cell surface membrane antigen, cytoskeletal protein and N-myc amplification and over-expression were analyzed in these cell lines and tumor tissues for the accurate diagnosis. NB and PNET could be distinguished from Ewing's sarcoma and RMS by the panel of monoclonal antibodies against cell surface membrane antigens. The cytoskeletal protein analysis is useful for the diagnosis of RMS and leiomyosarcoma. Alpha-smooth muscle actin and/or desmin were demonstrated in the S-type (epithelial-like) cells in 3 NB cell lines, suggesting the differentiation pathway of NB into smooth muscle cells. N-myc amplification and over-expression were observed in NB cell lines as well as one RMS cell line. The occurrence of N-myc amplification and over-expression in the RMS cell line cautions us against using N-myc as a distinguishable marker for NB.

Adolescent↗
PubMed2005

Ectopic expression of Par-4 leads to induction of apoptosis in CNS tumor cell lines.

Prostate apoptosis response-4 (Par-4) is a pro-apoptotic protein originally identified as a gene product upregulated in prostate tumor cells undergoing apoptosis. Down-regulation of Par-4 has been linked to several cancers. Since Par-4 also plays a crucial role in neuronal apoptosis, we investigated the expression of Par-4 in tumor cell lines derived from representative tumor types of the CNS, including primitive neuroectodermal tumor (PNET), medulloblastoma, neuroblastoma and glioma of human, rat and murine origin. We show that Par-4 is frequently down-regulated, either transcriptionally or post-transcriptionally in the CNS tumor cell lines. Moreover, we demonstrate that ectopic expression of Par-4 is sufficient to directly induce apoptosis in these CNS tumor cells, in contrast to other cancer cells where replenishment of Par-4 levels only sensitizes the cells to apoptotic stimuli. Induction of apoptosis by Par-4 in the neural tumor cell lines is independent of endogenous Bcl-2 levels and PKCzeta activity, although it has been proposed that Par-4 can exert its pro-apoptotic function by down-modulation of Bcl2 expression and inhibition of PKCzeta. Co-expression of Par-4 and a dominant-negative mutant of FADD resulted in a slight reduction of apoptosis in some tumor cell lines, indicating that Par-4 may partially induce apoptosis via the Fas death pathway. Furthermore, these data suggested that the pro-apoptotic function of Par-4 involves (an)other yet unidentified apoptotic pathway(s) in the CNS tumor cell lines. Since Par-4 by itself is not sufficient to induce apoptosis in non-tumor cells, reintroduction of Par-4 into primary CNS tumors or reactivation of the pathways of Par-4-mediated apoptosis represent promising targets in anti-tumor therapy.

Animals↗
PubMed1987

Experimental evidence for a neural origin of Ewing's sarcoma of bone.

The histogenesis of Ewing's sarcoma remains unknown. Recent studies have suggested a relationship to an unusual form of childhood neural tumor, often termed peripheral neuroepithelioma or primitive neuroectodermal tumor. Five Ewing's sarcoma tumor cell lines were studied for evidence of a neural phenotype. Under normal culture conditions, no morphologic evidence of neural differentiation was detected. Treatment with retinoic acid, an agent known to induce marked neural differentiation in neuroblastoma, had no demonstrable effect. Treatment with either cyclic AMP or TPA, in contrast, induced pronounced morphologic evidence of neural differentiation. Cells developed elongate processes with varicosities by phase-contrast microscopy; filaments, microtubules, and uraniffin-positive dense core granules were present by electron microscopy. Three neural markers (NSE, NFTP, and cholinesterase) were absent or barely detectable in untreated cells, but became abundant after treatment. These results provide convincing evidence for a neural histogenesis of Ewing's sarcoma. They also suggest a close relationship between Ewing's sarcoma and peripheral neural tumors, including the chest wall tumor described by Askin, but only a distant relationship to neuroblastoma.

Adolescent↗
PubMed1996

Predominant expression of human zic in cerebellar granule cell lineage and medulloblastoma.

Zic is a novel zinc finger protein which displays a highly restricted expression pattern in the adult and developing mouse cerebellum and is highly homologous to the recently cloned Drosophila pair-rule gene Opa. To clarify the mechanism for the development of the human cerebellum and its involvement in human nervous system diseases, we have isolated human Zic cDNA and examined its expression by using monoclonal antibody against recombinant Zic protein. The nucleotide sequence of human Zic cDNA is 85% homologous to that of mouse Zic cDNA. Its putative amino acid sequence is highly conserved (> 99%) except for substitution of only two amino acid residues. In situ chromosome hybridization localized the human Zic gene to chromosome band 3q24. Human Zic protein was immunohistochemically detected in the nuclei of the cerebellar granule cell lineage from the progenitor cells of the external germinal layer to the postmigrated cells of the internal granular layer. Furthermore, Zic protein was detected in medulloblastoma (26/29 cases), whereas no other tumors examined (over 70 cases including primitive neuroectodermal tumors) expressed this protein. These findings suggest that Zic is a potential biomarker for medulloblastoma as well as the human cerebellar granule cell lineage.

Adolescent↗
PubMed1998

The evolution of the diagnosis and understanding of primitive and embryonic neoplasms in children: living through an epoch.

Approximately 30% of malignant neoplasms in children are dysontogenetic tumors whose pathologic features resemble or recapitulate those of the developing organ or tissue of origin. Archetypes include classic neuroblastoma, Wilms' tumor, and embryonal rhabdomyosarcoma. This review traces the history of the principal types of dysontogenetic neoplasms and the primitive round cell tumors, Ewing's sarcoma, and peripheral primitive neuroectodermal tumor. Retinoblastoma, neuroblastoma, and Wilms' tumor were first described in the 19th century but with several different appellations than those we use today. Although some progress was made in the surgical management of Wilms' tumor during the 1940s and 1950s, most of these unique solid neoplasms of childhood were seen as essentially untreatable and inevitably fatal; surgery and perhaps irradiation were the principal therapeutic offerings. The folic acid analogue, aminopterin, was reported in 1948 as inducing the first complete but temporary remission in acute childhood leukemia. The chemotherapeutic era began shortly thereafter with effective chemotherapy in the management of Wilms' tumor with the introduction of dactinomycin. Pathologists were no longer restricted to being purveyors of the death sentence; they were now responsible for differentiating one type of primitive and embryonic neoplasm from another by using a variety of ancillary techniques, including tissue culture, electron microscopy, immunohistochemistry, and cytogenetics. Favorable or unfavorable morphologic types and subtypes of tumors were defined and, together with the pathologic staging, became incorporated into the therapeutic plan and prognostic assessment. During the past 40 years, these tumors progressed from being virtually treatment resistant to having an overall 5-year survival of 70% or greater. Through the cooperative efforts of pediatric hematologists/oncologists, pediatric surgeons, radiation therapists, and pathologists, the primitive and embryonic neoplasms of childhood are now viewed as some of the most treatable and curable of cancers.

Child↗
PubMed1998

Small round-cell type of malignant peripheral nerve sheath tumor.

Five cases of primitive, small, round-cell tumor that are a type of hitherto unclassified neurogenic sarcoma are described. The tumors were located deep within the soft tissue of the trunks and limbs without association with major nerves. The histologic features consisted mainly of uniform, small, round, tumor cells with scanty cytoplasm. Foci of uniform, short, spindle-shaped tumor cells arranged in whorl-like patterns were observed in some areas. Although the immunoreactivity for the neural markers, Leu-7 and MIC-2, was not marked, cell processes and fragmentous basal laminae, which are ultrastructural neural features, were found in both spindle-shaped and round tumor cells. In four cases, EWS chimeric transcripts were analyzed by reverse-transcription polymerase chain reaction. EWS chimeric mRNA (EWS-FLI-1, EWS-ERG, EWS-E1AF, EWS-ETV1, EWS-FEV) was not detected in any cases. The tumors were not consistent with peripheral primitive neuroectodermal tumor. We propose them as a small round-cell type of MPNST that might differentiate toward the immature neural cells.

Adolescent↗
PubMedDate not supplied

[Orbital tumors in children. Transcranial surgical approach].

From March 1980 to December 1995, at the Department of Neurosurgery of the Instituto Nacional de Pediatría (INP), 23 patients were treated for orbital tumors. In this communication, the authors report on the clinical presentation, age, radiological findings, visual-evoked potentials, type of surgery, histological diagnosis, and results. Two kinds of surgical techniques were employed: craniotomy with orbital roof removal (NAFZIGER) and fronto-orbitotomy. Eleven patients had optic nerve gliomas, 3 had fibrous osseous dysplasia, 2 meningiomas, neurofibromas, Langerhans cells histiocytosis, and 1 case of Anaplastic astrocytoma, Teratoma, primitive Neuroectodermal tumor, germinoma with areas of choriocarcinoma. The results were evaluated for the quality of life in regard to the Karnofsky scale, tumor recurrence and postoperative visual-evoked potentials. It is important to note the very variable histological kinds of lesions found in this series that can be approached surgically with cranio orbitotomy with good results.

Adolescent↗
PubMed2000

Prolonged cerebral salt wasting syndrome associated with the intraventricular dissemination of brain tumors. Report of two cases and review of the literature.

Hyponatremia is a frequent event in neurosurgery practice and is usually associated with subarachnoid hemorrhage, head trauma, infections and neoplasms. The two common clinical manifestations are the inappropriate secretion of antidiuretic hormone (SIADH) and the cerebral salt wasting syndrome (CSWS), which were usually attributed to each other due to identical clinical presentation. In contrast to the better-recognized SIADH, there has not been a uniform consensus over the humoral and neural mechanisms of CSWS and functional aspects of renal response. In this article, we report on 2 cases of a primitive neuroectodermal tumor with prolonged CSWS manifested during the intraventricular dissemination of primary disease and the high catabolic stage.

Brain Diseases, Metabolic↗
PubMed2001

Foreign body reaction to hemostatic materials mimicking recurrent brain tumor. Report of three cases.

Chemical agents routinely used in neurosurgery to achieve intraoperative hemostasis can cause a foreign body reaction, which appears on magnetic resonance (MR) images to be indistinguishable from recurrent tumor. Clinical and/or imaging evidence of progression of disease early after surgical resection or during aggressive treatment may actually be distinct features of granuloma in these circumstances. A series of three cases was retrospectively analyzed for clinical, imaging, surgical, and pathological findings, and the consequences they held for further disease management. All patients were boys (3, 3, and 6 years of age, respectively) and all harbored primitive neuroectodermal tumors. Two tumors were located in the posterior fossa and one was located in the right parietal lobe. Two boys exhibited clinical symptoms, which were unexpected under the circumstances and prompted new imaging studies. One patient was asymptomatic and imaging was performed at planned routine time intervals. The MR images revealed circumscribed, streaky enhancement in the resection cavity that was suggestive of recurrent disease. This occurred 2 to 7 months after the first surgery. At repeated surgery, the resected material had the macroscopic appearance of gelatin sponge in one case and firm scar tissue in the other cases. Histological analysis revealed foreign body granulomas in the resected material, with Gelfoam or Surgicel as the underlying cause. No recurrent tumor was found and the second surgery resulted in imaging-confirmed complete resection in all three patients. Because recurrent disease was absent, the patients continued to participate in their original treatment protocols. All patients remain free from disease 34, 32, and 19 months after the first operation, respectively. During or after treatment for a central nervous system neoplasm, if unexpected clinical or imaging evidence of recurrence is found, a second-look operation may be necessary to determine the true nature of the findings. If the resection yields recurrent tumor, additional appropriate oncological treatment is warranted, but if a foreign body reaction is found, potentially harmful therapy can be withheld or postponed.

Brain↗
PubMedDate not supplied

Pediatric neuroblastic brain tumors containing abundant neuropil and true rosettes.

We have encountered a series of seven unusual neuroblastic pediatric central nervous system (CNS) neoplasms with a unique constellation of histologic, immunohistochemical, and ultrastructural features. The tumors presented in five girls and two boys, ages 1 to 3 years. In six cases the lesions involved the frontoparietal region, in one case the tectal plate. The tumors consisted of small to medium-sized, round to oval, hyperchromatic cells with poorly defined cytoplasmic borders. Cells were found in clusters and cords set in a paucicellular fibrillar neuropil matrix. Distinctive, virtually anuclear regions of neuropil were scattered throughout the lesions. True rosettes with well-formed central lumens often filled with granular debris were present, along with perivascular pseudorosettes and occasional Homer-Wright rosettes. Mitoses and apoptosis were frequent, but large regions of confluent necrosis were absent. Immunohistochemically, the neuropil-like areas as well as the perinuclear cytoplasm of many embryonal tumor cells were positive for synaptophysin and neurofilament protein. Ultrastructurally, the tumor cells showed microtubule-containing neuronal processes, some with neurosecretory granules. While the lesions were largely glial fibrillary acidic protein (GFAP) negative, there was focal GFAP positivity consistent with divergent differentiation in one case. The clinical outcome was poor, with five patients dead from their disease 5 to 14 months after initial presentation and one patient with recurrent disease 7 months after resection and chemotherapy. The final patient is alive without recurrent disease 30 months after initial presentation. These lesions present distinctive histological features within the group of primitive neuroectodermal tumors.

Apoptosis↗