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PubMed1985

Embryonal central neuroepithelial tumors and their differentiating potential. A cytogenetic view of a complex neuro-oncological problem.

The embryonal central nervous system (CNS) neoplasms are reviewed with special reference to their differentiating potential and in the light of current neuro-oncogenetic concepts partly derived from the experimental induction of neural tumors. The conceptual (and, occasionally, practical) distinction between adult-type and embryonal CNS tumors raises a complex problem, because neoplastic transformation essentially involves replicating stem cells in tissues of renewal and because in the human brain such cells are found mostly in the course of CNS development. A cytogenetic scheme is therefore needed to serve as a frame of reference for a classification of embryonal CNS tumors that will account for the different histological entities documented so far and for the range and the restrictions of their differentiating capabilities. Most embryonal CNS tumors can be fitted into such a scheme. The cerebral medulloepithelioma, the cerebral and cerebellar neuroblastomas, the primitive polar spongioblastoma, and the ependymoblastoma show characteristic morphological features and a correspondingly distinctive cellular differentiating potential. The differentiating capabilities of the cerebellar medulloblastoma, the pineoblastoma, and the retinoblastoma are also distinctive, and are apparently determined by the cytogenesis of the area of the CNS in which the tumors originate. The indiscriminate application of a simplistic concept that would include all the so-called "primitive neuroectodermal tumors" into a single neuroepithelial tumor entity is unlikely to bring further understanding to the problem.

Age Factors↗
PubMed1994

FNA biopsy of small round cell tumors of childhood: cytomorphologic features and the role of ancillary studies.

Pediatric tumors which are conventionally considered to be small round cell tumors (SRCTs) include the prototypical neuroblastoma as well as rhabdomyosarcoma (RMS), Ewing's sarcoma (ES), malignant lymphoma, and primitive neuroectodermal tumor (PNET). Other malignancies may be considered in the differential diagnosis such as small-cell osteogenic sarcoma, undifferentiated (anaplastic) hepatoblastoma, granulocytic sarcoma, blastemal type Wilms' tumor, and desmoplastic small-cell tumor of the peritoneum. The cytomorphologic features of conventional SRCTs is presented as well as the utility of ancillary studies performed on the aspirated material in making a specific and correct diagnosis. The role of the immediate cytologic assessment of the aspirate is stress, since this is a critical step in formulating an initial diagnostic impression that should prompt the need for additional material for pertinent ancillary studies. Although challenging, FNA cytology of SRCTs of childhood can be diagnostic in the majority of cases, allowing specific therapy to be given to patients with unresectable SRCTs without a tissue biopsy as well as documenting recurrent and/or metastatic disease.

Adolescent↗
PubMed1996

Central nervous system medulloepithelioma: a series of eight cases including two arising in the pons.

Medulloepithelioma is an uncommon childhood tumor of the central nervous system (CNS) whose histopathological appearance has been confused with medulloblastoma and other childhood primitive neuroectodermal tumors (PNETs), but which has a vastly different clinical course. The authors have reviewed the clinical features and treatment responses of eight children with these rare tumors, the largest series to date. In this series, the medulloepitheliomas were equally distributed between supratentorial and infratentorial primary sites. Four patients underwent gross- or near-total resections, one patient's tumor was partially resected, and one patient had biopsy only. Biopsy and ablative surgery were not attempted in two children with pontine tumors. Treatment included both radiation and chemotherapy (four patients), radiation alone (one patient), chemotherapy alone (one patient), and no post-operative treatment (two patients). Six patients died with a mean survival of 10 months and two are disease free with neurological impairment. Both long-term survivors underwent gross-total resections of their tumors. Postmortem examination revealed diffuse CNS tumor dissemination in four patients. Medulloepithelioma, often confused with less aggressive PNETs, can mimic intrinsic brainstem glioma, responds poorly to treatment, and is prone to CNS dissemination at the time of tumor progression.

Brain Neoplasms↗
PubMed1993

Family history of cancer and seizures in young children with brain tumors: a report from the Childrens Cancer Group (United States and Canada).

The occurrence of cancer and neurological disorders in first- and second-degree relatives of children in the United States and Canada diagnosed with brain tumor before age six was investigated. A pair-matched case-control study with 155 astrocytoma and 166 primitive neuroectodermal tumor (PNET) cases was performed. Cases were identified through the Childrens Cancer Group. Controls were selected by random-digit dialing and matched to cases on age, race, and telephone area code and exchange. Childhood cancers were more common in PNET relatives compared with the general population (standardized incidence ratio [SIR] = 2.5, 95 percent confidence interval [CI] 1.1-4.8, P = 0.02) and with control relatives (odds ratio [OR] = 3.0, CI = 0.5-30, P = 0.29). For astrocytoma, nonsignificant excesses of brain tumor, leukemia/lymphoma, and childhood cancer occurred among case relatives compared with control relatives, but not compared with the general population. Astrocytoma cases were significantly more likely than controls to have a relative with seizures (OR = 2.5, CI = 1.2-4.9, P = 0.009), especially childhood seizures (OR = 3.4, CI = 1.2-12, P = 0.02), epilepsy (OR = 3.0, CI = 0.9-13, P = 0.08), and febrile convulsions (OR = 4.5, CI = 0.9-43, P = 0.07). A family history of stroke was not a risk factor for either type of brain tumor. These results suggest that some childhood brain tumors may result from a genetic susceptibility and that some risk factors may affect childhood astrocytoma and PNET differently.

Adult↗
PubMed2000

EWS fli-1 antisense nanocapsules inhibits ewing sarcoma-related tumor in mice.

EWS Fli-1, a fusion gene resulting from a t(11;22) translocation is found in 90% of both Ewing's sarcoma and primitive neuroectodermal tumor (PNET). In the present study, we show that recently developed polyisobutylcyanoacrylate nanocapsules with an aqueous core were able to encapsulate efficiently high amounts of phosphorothioate oligonucleotides (ODN) directed against EWS Fli-1 chimeric RNA. Release of these ODN in serum medium was shown to be biphasic which was explained by the presence of two types of nanocapsules able to release ODN with different kinetics. In addition, nanocapsules were found to provide protection of these oligonucleotides from the degradation in serum. These ODN nanocapsules permitted to obtain inhibition of Ewing sarcoma-related tumor in mice after intratumoral injection of a cumulative dose as low as 14.4 nanomoles. This new type of non viral vector shows great potential for in vivo administration of oligonucleotides.

3T3 Cells↗
PubMedDate not supplied

Improvement of the methylation specific PCR technical conditions for the detection of p16 promoter hypermethylation in small amounts of tumor DNA.

Methylation specific PCR (MSP) is a technique that enables the detection of hypermethylation at a CpG island. The objective of this study is the introduction of small modifications to the MSP technique to make it more suitable for the study of promoter hypermethylation at tumor suppressor genes whenever there is a shortage of material available for study. This commonly happens in the case of using archival material from the Pathology departments. Tumor DNA was extracted from a collection of 40 fresh-frozen soft tissue sarcomas and 19 paraffin-embedded PNETs (primitive neuroectodermal tumors). The MSP technique was performed to detect hypermethylation at the p16 promoter. Also, blood genomic DNA was mixed with herry sperm genomic DNA as a carrier, in nine different combinations, in order to test for the best conditions that could produce MSP bands even when low amounts of genomic tumor DNA is available for study. We demonstrate the benefit of using herry sperm carrier DNA up to 10 microg together with small quantities of tumor DNA. This result will facilitate the incorporation of paraffin-embedded samples for study of promoter hypermethylation at tumor suppressor genes. Other technical conditions for the MSP technique are also studied.

Brain Neoplasms↗
PubMed1993

Immunohistochemical evaluation of dystrophin expression in small round cell tumors of childhood.

Dystrophin, the protein product of the Duchenne muscular dystrophy locus, is a major component of the subsarcolemmal cytoskeleton in skeletal muscle cells and is a relatively muscle specific protein. We evaluated, retrospectively, the expression of dystrophin in 23 small round cell tumors of childhood including: 9 rhabdomyosarcomas, 4 neuroblastomas, 1 ganglioneuroblastoma, 2 small noncleaved cell lymphomas, 1 lymphoblastic lymphoma, 2 medulloblastomas, 2 primitive neuroectodermal tumors, 1 Wilms' tumor, and 1 undifferentiated sarcoma. Frozen sections were stained by the avidin biotin immunoperoxidase technique using a commercially available monoclonal antibody NCL-DYS1 (Novocastra) that recognizes the mid-rod domain (between amino acids 1181 and 1388) of human dystrophin. Positive controls were represented by frozen sections of normal skeletal muscle. Negative controls consisted of substituting the dystrophin antibody for normal rabbit serum. Eight of nine rhabdomyosarcomas revealed positivity whereas, none of the other tumors stained for dystrophin. This study provides evidence that monoclonal antibodies to dystrophin may be a potential useful addition to the panel of muscle markers used to diagnose small round cell tumors of childhood.

Adult↗
PubMed2000

Embryonal tumors in the adult population: implications in therapeutic planning.

The natural history of neuroectodermal tumors is still debated as far as prognostic factors are concerned; the same uncertainty applies to the optimal radiotherapy schedule and even more to the presumptive additive effect of chemotherapy. The rarity of these tumors and the heterogeneity of management make interpretation of literature data also more difficult. We evaluated clinical course in a cohort of 39 patients, including 31 with medulloblastoma (MB) and 8 with primitive neuroectodermal tumors (PNET). All patients were treated with radiotherapy, a standardized chemotherapy protocol including PCV scheme, and a second-line chemotherapy with cisplatin and etoposide (VP16) at recurrence. In 27 patients, intrathecal chemotherapy was also delivered. Median follow-up was 10.8 years. Overall, PNET had a worse outcome as compared to MB: median survival times were 42.8 vs. 92.6 months, respectively (p = 0.05). At 5 years, 45% of MB patients are alive. No significant difference in disease-free period was found between patients of different age, desmoplastic variant, tumor localization, or extent of surgery. Patients considered to be "high risk" had a significantly shorter disease-free period as compared with low-risk patients (27 vs. 54.7 months, p = 0.04). Systemic or intrathecal chemotherapy did not influence progression-free survival (PFS). However, in the majority of chemotherapy-treated patients, a low-dose craniospinal radiotherapy was also delivered. This combination of treatments may have avoided the expected increased percentage of failure. Moreover, more than half of recurrent patients had a partial response to chemotherapy that extended survival for approximately 3 years. Repeated surgery and chemotherapy at recurrence favorably influenced survival time.

Adult↗
PubMed1997

Expression of type I interferon receptor in solid tumors of childhood.

Interferon alpha (IFN alpha) is used as an antineoplastic agent, both in hematopoietic malignancies and in solid tumors, because of its immunomodulatory action and direct antitumor activity. IFN alpha binds to specific cell-surface receptors that mediate its biologic activity. We studied the expression of IFN alpha receptors in pediatric solid tumors by use of the monoclonal antibody IFNaR3, which specifically recognizes the alpha subunit of the IFN Type I receptor. In three cell lines derived from those tumors, we determined the structure of the receptors by affinity cross-linking and immunoprecipitation techniques, and we determined their ability to mediate an antiproliferative effect. All of the tumor specimens studied by immunocytochemical analysis, including neuroblastomas, primitive neuroectodermal tumors, and rhabdomyosarcomas, stained positive for the IFN alpha receptor antibody, although in some cases immunoreactivity was weak. The three cell lines, derived from a neuroblastoma, a primitive neuroectodermal tumor, and a Ewing's sarcoma, respectively, showed the same pattern of IFN alpha receptor expression, both by affinity crosslinking and immunoprecipitation assays. Treatment with IFN alpha of those cell lines induces growth inhibition in vitro. These results suggest that IFN Type I receptor might be expressed in most solid tumors of childhood and that its structure is identical to the receptor expressed by the majority of hematologic malignancies.

Adolescent↗
PubMed1999

Relation of neurological marker expression and EWS gene fusion types in MIC2/CD99-positive tumors of the Ewing family.

The Ewing family of tumors (EFT) is characterized by high MIC2/CD99 expression and specific EWS/ETS gene rearrangements, resulting in different chimeric transcripts. Further division into peripheral primitive neuroectodermal tumors and Ewing's sarcoma is still debated and, in the absence of distinct morphological parameters, has been based on the reactivity with neuroglial markers (NgM). We investigated 44 EFT in terms of a possible correlation between the type of EWS chimeric transcripts and reactivity with the following NgM: polyclonal and monoclonal neuron-specific enolase (NSE), S-100, chromogranin A, synaptophysin, Leu-7, glial fibrillary acid protein, and neurofilament. EWS/Fli1 fusion type 1 was detected in 30 of 44 and type 2 in 11 of 44 tumors. Three tumors, presenting with an uncommon morphology, carried rare chimeric transcripts. Our results indicate an association of lack of NgM staining with type 1 EWS/Fli1 translocations, found in 16 of 18 tumors with no NgM expression as detectable by any of the antibodies we applied. Using the monoclonal NSE antibody, 21 of 26 tumors without NgM staining expressed type 1 EWS/FLI1chimeric RNA, whereas in the groups with 1 or more and 2 or more NgM, only 9 of 17 and 1 of 5 tumors, respectively, carried type 1 EWS/Fli1 fusion transcripts. Despite this association of increased NgM expression with a non-type 1 EWS/Fli1 gene fusion, a strict correlation between the extent of NgM expression and certain EWS fusion types was not evident. This fortifies the concept to consider EFT as a spectrum of tumors and suggests the type of EWS fusion transcripts as one, but not the only parameter influencing the extent of differentiation.

Adolescent↗
PubMed2005

A 15-year-old female with progressive myelopathy.

March 2005. A 15-year-old female presented with urinary retention, inability to walk and low back pain. MRI disclosed an elongated epidural mass in the thoracic spine with cord compression and invasion into the surrounding bone and soft tissue. Cytologic preparation at intraoperative consultation disclosed a rather monotonous small tumor cells with hyperchromatic nuclei and vacuolated cytoplasm. These vacuoles were best visualized with DiffQuick stain. Pathologic studies revealed an Ewing sarcoma/peripheral primitive neuroectodermal tumor (EWS/pPNET) with typical features including periodic acid Schiff positive diastase sensitive cytoplasmic substance; strong membranous pattern of immunoreactivity for CD99, and a reciprocal translocation of t(11;22)(q24;q12) that was demonstrated by fluorescent in situ hybridization (FISH). The vacuolated cytoplasm was produced by glycogen as demonstrated by electron microscopy. Although primary vertebral EWS/pPNETs are uncommon, they should be considered in the differential diagnoses of extradural/epidural mass of the spine in young patients.

Adolescent↗
PubMed2001

Aberrant promoter methylation of previously unidentified target genes is a common abnormality in medulloblastomas--implications for tumor biology and potential clinical utility.

Medulloblastomas exhibit an array of diverse cytogenetic abnormalities. To evaluate the significance of epigenetic rather than genetic lesions in medulloblastomas and other primitive neuroectodermal tumors (PNETs) of the childhood CNS we performed a systematic analysis of gene specific and global methylation. Methylation-specific PCR detected no methylation for p15(INK4B), von Hippel Lindau and TP53 and only limited methylation for E-Cadherin and p16(INK4A) in tumors. The cell lines Daoy and MHH-PNET-5 in which the p16(INK4A) promoter was methylated did not express the gene, but demonstrated abnormalities by SSCP. Immunohistochemistry for p16 was negative in all examined normal cerebella and medulloblastomas. Using the technique of Restriction Landmark Genomic Scanning we detected methylation affecting up to 1% of all CpG islands in primary MB/PNETs and 6% in MB cell lines. Methylation patterns differed between medulloblastomas and PNETs. Examination of several methylated sequences revealed homologies to known genes and expressed sequences. Analysis of survival data identified seven of 30 hypermethylated sequences significantly correlating with poor prognosis. We suggest that DNA hypermethylation has an outstanding potential for the identification of novel tumor suppressors as well as diagnostic and therapeutic targets in MBs and other PNETs of the CNS.

Adolescent↗
PubMedDate not supplied

Expression of proline-directed protein kinase, (p34cdc2/p58cyclin A), a novel cell proliferation marker in childhood brain tumors.

The presence of two proteins of the proline-directed protein kinase (PDPK), the catalytic subunit p34cdc2 and the regulatory subunit p58cyclin A was determined in seven primitive neuroectodermal tumors (PNETs), three choroid plexus neoplasms and eleven astroglial tumors. The highest expression was registered in the cellularly undifferentiated PNETs and glioblastoma multiforme from the astroglial malignant group. Rabbit immunoantiserum against the two subunits of PDPK, a cell proliferation marker, was employed to detect proliferation activity in childhood brain tumors. The PDPK activity was present from Gl- to M-phases in 21 childhood brain tumors with different central nervous system (CNS) localization and cellular atypia. Immunocytochemical analysis employed an indirect, alkaline phosphatase conjugated biotin-streptavidin antigen detection technique on frozen and routine, formalin-fixed and paraffin-wax-embedded tissue sections of brain tumors. We compared the proliferation activity in the cells of normal, morphologically changed and neoplastically transformed choroid plexus. The average proliferation activity was low in comparison with other tissues. The results in normal and neoplastically transformed choroid plexus were very similar. The lowest proliferation activity in the astroglial group belonged to pilocytic ASTRs. The use of cell differentiation as a prognostic factor in primary brain tumors has already been established and is strongly suggested by our research group. Further systematic neoplasm studies and regular employment of these two polyclonal antibodies for immunocytochemical screening experiments are necessary to determine their true diagnostic and prognostic significance.

Adolescent↗
PubMed2002

Analysis of cytogenetic aberrations in esthesioneuroblastomas by comparative genomic hybridization.

Esthesioneuroblastoma (ENB) are rare tumors originating from the olfactory epithelium of the superior nasal cavity. This lesion is morphologically closely related to Ewing sarcoma and other peripheral primitive neuroectodermal tumors (pPNET). The affiliation of ENB to the pPNET family is still under discussion. Only very limited and contradictory cytogenetic data are available on ENB and only one patient has been analyzed by comparative genomic hybridization (CGH), so far. In the present study, genomic imbalances of three ENB were analyzed by CGH to evaluate (1) a recurrent pattern of imbalances, and (2) its relation to the pPNET family. The CGH analysis of three ENB revealed multiple recurrent aberrations including DNA overrepresentations of chromosomal material of the entire chromosome 19, partial gains of the long arms of chromosomes 8, 15, and 22, and deletions of the entire long arm of chromosome 4. Beside these common aberrations, several single gains and losses occurred, that is, gains on 6p, 10q, 1p, 9q, and 13q. We confirmed the former observation of amplified genetic material on chromosome 8 and found several new, currently not described recurrent genetic aberrations distinct from those described for pPNET. Our findings give evidence that ENB is not part of the pPNET family. We suggest that the combined gain of genetic material on 15q, 22q, and chromosome 8 might be indicative for ENB. To verify our findings and to define prognosis-related aberrations, a larger number of cases needs to be studied.

Aged↗
PubMed1997

Clear cell tumors of bone.

Except for clear cell carcinomas that metastasize to bone, with renal cell carcinoma being the principal representative of that group, clear cell osseous neoplasms are rare. The only distinct nosologic entity in this category that is primary in the bone is the clear cell chondrosarcoma (CCCS). This lesion, which is most often seen in the proximal femur or humerus, affects males more often than females and has a peak incidence during the third and fourth decades of life. Radiologic images of CCCS show a well-circumscribed, often calcified lytic lesion that may expand the bone, but only uncommonly breaches the cortex. Clear cell elements in CCCS are accompanied by "conventional" foci of chondrosarcoma in less than 50% of cases; noncartilaginous "secondary features," including areas of osteogenesis, osteoclast-like giant cells, and zones resembling aneurysmal bone cyst or giant cell tumor of bone, may be apparent as well. CCCS is a relatively indolent malignancy; roughly 25% of patients experience local recurrences of their tumors or suffer metastasis, but tumor-related death is uncommon, particularly when the lesion has been completely resected en bloc. Sporadic examples of other tumors in bone also may be focally or entirely composed of clear cells. These include osteosarcoma, chondroblastoma, chordoma, adamantinoma, Ewing's sarcoma, and primitive neuroectodermal tumor. The last two of these lesions represent the most common primary clear cell bone tumors in children, whereas metastatic renal clear cell sarcoma is the most frequent metastatic pediatric tumor in this category.

Biomarkers, Tumor↗
PubMed2000

Molecular biology of the Ewing's sarcoma/primitive neuroectodermal tumor family.

Ewing's sarcoma (ES) and primitive neuroectodermal tumor (PNET) are members of a tumor family consistently associated with chromosomal translocation and functional fusion of the EWS gene to any of several structurally related transcription factor genes. Similar gene fusion events occur in other mesenchymal and hematopoietic tumors and are tumor-specific. The resulting novel transcription factor-like chimeric proteins are believed to contribute to tumor biology by aberrant regulation of gene expression altering critical controls of cell proliferation and differentiation. These tumor-specific molecular rearrangements are useful for primary diagnosis, may provide prognostic information, and present potential therapeutic targets. The recent advances in our understanding of the molecular biology of ES and PNET represent a paradigm for the application of the basic biology of neoplasia to clinical management of patients.

Cell Transformation, Neoplastic↗
PubMed2000

Immunohistochemistry of small round-cell tumors.

The term "small round-cell tumor" describes a group of highly aggressive malignant tumors composed of relatively small and monotonous undifferentiated cells with high nuclear to cytoplasmic ratios. This group includes Ewing's sarcoma (ES), peripheral neuroepithelioma (aka, primitive neuroectodermal tumor or extraskeletal ES), peripheral neuroblastoma ("classic-type"), rhabdomyosarcoma, desmoplastic small round-cell tumor, lymphoma, leukemia, small-cell osteosarcoma, small-cell carcinoma (either undifferentiated or neuroendocrine), olfactory neuroblastoma, cutaneous neuroendocrine carcinoma (aka, Merkel-cell carcinoma), small-cell melanoma, and mesenchymal chondrosarcoma. Their clinical presentations often overlap, thus making a definitive diagnosis problematic in some cases. Yet, a clear understanding of their clinicopathologic features usually allows for a confident diagnosis, especially if immunohistochemistry is used. The following is a review of the immunohistochemistry of this small round-cell tumor group.

Biomarkers, Tumor↗
PubMed1996

Histology, immunohistochemistry, and electron microscopy of small round cell tumors of bone.

Small round cell tumors (SRCTs) of the bone make up a family of primary bone sarcomas with morphologically, biologically, and clinically specific features. Among them, Ewing's sarcoma (ES) is the most common entity, but several varieties such as atypical ES, large cell ES, and ES with neuroectodermal differentiation (peripheral primitive neuroectodermal tumor of the bone or neuroepithelioma of the bone) have been identified recently. Histology and electron microscopy together with the variable expression of several epitopes (as shown by immunohistochemistry, mainly HBA/71 [Mic2 antigen]) provide the basis for characterizing the group within the context of neuroectodermal-derived neoplasms. A number of other ES-like tumors with small round cells, mimicking those previously described, have been characterized; Askin's tumor of the thoracopulmonary region will be considered as an ES similar to those already described, but within a particularly anatomic location. On the other hand, the presence of an endothelial appearance within a poorly differentiated neoplasm may be present in some ES-like SRCTs (atypical ES with endothelial features). The differential diagnosis with other sarcomas defined by small round to spindle cell contours might prove difficult. Particular attention must be paid to small cell osteosarcoma and mesenchymal chondrosarcoma. Likewise, "primitive sarcoma of bone" is considered in this study because it is a very rare neoplasm differing from the formerly discussed types; its pluripotentiality provides this tumor a blastemic character and a multiphenotypic expression. Malignant non-Hodgkin's lymphoma is an unusual presentation when primary to the bone, previous to any other anatomic location. Several subtypes have been considered within a histology that encompasses that seen in lymph nodes.

Bone Neoplasms↗