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PubMedDate not supplied

Pediatric core needle biopsy: strengths and limitations in evaluation of masses.

Needle core biopsies (NCB) are widely used in adults but are less often used for the evaluation of pediatric tumors. To determine the diagnostic utility of NCB for pediatric tumors, we performed a retrospective analysis. Fifty NCB of masses from 1992 to 1998, subsequent pathologic specimens, and medical records were reviewed. All patients were less than 21 years of age. Of the NCB 78% (39/50) were diagnostic of a neoplasm, 8% (4/50) were nondiagnostic in cases where a tumor was subsequently diagnosed, and 14% (7/50) revealed inflammatory or reactive lesions, with no subsequent diagnosis of a neoplasm according to medical record review. In cases in which a neoplasm was present, NCB was diagnostic in 91% (39/43). For cases in which there was a previous diagnosis of a tumor, 100% (9/9) of NCB were diagnostic of a recurrence or metastasis. In cases of NCB for primary tumor diagnosis, 88% (30/34) were diagnostic. The most common problems encountered were related to specimen adequacy, such as insufficient tissue, crush artifact, and tumor necrosis. Tumor diagnoses were as follows: primitive neuroectodermal tumor (PNET)/Ewing sarcoma (12), malignant lymphoma/Hodgkin's disease (8), rhabdomyosarcoma (4), germ cell tumor (3), Wilms' tumor (3), neuroblastoma (1), sarcoma, not otherwise specified (4), and other neoplasms (8). There were no complications of the procedure. NCB of pediatric tumors is an effective diagnostic tool and can be used to obtain diagnostic material quickly and safely. NCB was diagnostic in 90% of cases in this series. When NCB provide sufficient material for immunohistochemical, cytogenetic, flow cytometric, and other ancillary studies, the diagnostic efficacy is enhanced. The major limitations in this series were related to sampling problems and specimen adequacy for comprehensive pathologic evaluation.

Adolescent↗
PubMed2005

Differentiating imaging findings in primary and secondary tumors of the jugular foramen.

The preoperative diagnosis of a jugular foramen tumor may be challenging, since a large variety of unusual lesions may be located in this region. These tumors may be classified as primary lesions (which are located in the jugular foramen or extend from the jugular foramen into the surrounding structures) and as secondary lesions (that extend from the surrounding structures into the jugular foramen). Primary tumors include glomus jugulare tumors, schwannomas, meningiomas and peripheral primitive neuroectodermal tumors, while secondary tumors comprise chordomas, chondrosarcomas, chondroblastomas, giant-cell tumors, cholesterol granulomas, giant cholesterol cyst, endolymphatic sac tumors, reactive myofibroblastic tumors, temporal bone carcinomas and metastases. Accurate preoperative radiological suspicion is of great value for preoperative patient counseling and has a direct impact on the surgical planning in these cases. The present study describes and discusses the main differentiating imaging features of lesions involving the jugular foramen, whose accurate preoperative radiological evaluation is essential for proper surgical planning.

Brain Neoplasms↗
PubMed2000

Preliminary individual adjuvant therapy for gliomas based on the results of molecular biological analyses for drug-resistance genes.

New adjuvant therapy individualized by the results of reverse transcription-polymerase chain reaction (RT-PCR) for drug-resistance genes has been used to treat malignant gliomas. Protocol studies for malignant gliomas were not so encouraging in their therapeutic results because of heterogeneity and the various drug-sensitivities of the tumors. Individualization of glioma therapy is recommended. Drug-resistance genes messenger ribonucleic acid (mRNA) expressions were investigated in drug-resistant human glioma cell lines derived from U87MG and 46 frozen samples of retrospectively examined neuroepithelial tumors (12 low grade neuroepithelial tumors, 16 Grade III gliomas, 11 glioblastomas, and 7 other malignant neuroepithelial tumors such as medulloblastomas and primitive neuroectodermal tumors) by RT-PCR with the specific primers for O6-methylguanine DNA methyltransferase (MGMT), multidrug-resistance gene 1 (MDR1), multidrug-resistance-associated protein (MRP), and glutathione-S-transferase-pi (GST-pi). Thirty-seven preliminary individual adjuvant therapies (IAT) based on RT-PCR results, mainly in MGMT expression, were performed on 30 consecutive patients with neuroepithelial tumors. In the retrospectively examined series, the initial response to 1-(4-amino-2-methyl-5-pyrimidynyl) methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) was correlated most significantly to the MGMT mRNA expression among 11 independent prognostic factors (p = 0.0037) in multivariate logistic regression analysis. In the preliminary IAT, 17 of 32 evaluable therapies had a partial or complete response (53.1% response rate). Our IAT based on RT-PCR seemed to be more effective than conventional therapies for malignant gliomas.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2002

Mutation analysis of human cytokeratin 8 gene in malignant rhabdoid tumor: a possible association with intracytoplasmic inclusion body formation.

The rhabdoid cell, which is typically observed in malignant rhabdoid tumor (MRT) and other malignant neoplasms, has an eosinophilic cytoplasm containing a spheroid perinuclear inclusion body. This distinct cell is known to act as a highly aggressive indicator in many types of malignant tumors and is characterized by aggregates of intermediate filaments, comprising both vimentin and cytokeratin (CK) 8, which is mainly expressed in simple-type epithelium such as liver and intestine. To clarify the cause of the inclusion body formation, we analyzed the alteration of the complete human CK8 gene (KRT 8: 1724 base pairs) in seven samples of MRT (three from frozen materials and four from cultured cell lines) by reverse-transcriptase polymerase chain reaction, followed by direct sequencing. In addition, the two cell lines, Huh7 and HeLa, which lacked rhabdoid feature, six pediatric malignant tumors, including three cases of primitive neuroectodermal tumor (PNET) and three of Wilms' tumor; and 15 normal liver tissue (as a control) were also analyzed. All MRT samples had missense mutations in the human KRT 8 gene, i.e., Arg89 --> Cys (5/7); Arg --> Cys251 (3/7); Glu267 --> Lys (6/7); Ser290 --> Ile, Met; (7/7) and Arg301 --> His(4/7), none of which was detected in any control samples. Among these mutations, the most noteworthy findings were that Arg89 belongs to the H1 subdomain of the head domain and that Arg251 belongs to the short nonhelical linker segment, or L1-2. Both these mutations are noted for their relationships to lateral protofilament-protofilament interactions. In addition, Ser290 has been previously reported to be a phosphorylation site, which has been recognized to play an important role in filament organization, leading to conformational change of the CK8 filaments. In conclusion, mutated codons of CK8 gene in MRT were located in the important region involved in the conformational change of intermediate filament.

Amino Acid Sequence↗
PubMed1994

Cytogenetics and experimental models of sarcomas.

Many sarcomas contain characteristic chromosome translocations that result in the fusion of genes from two different chromosomes. This review focuses on the translocated genes that have been identified recently in Ewing's sarcoma, peripheral primitive neuroectodermal tumor, clear cell sarcoma, alveolar rhabdomyosarcoma, and myxoid liposarcoma. Each of these fusion genes encodes a DNA transcription factor that presumably regulates the function of other genes. Thus, a common mechanism of oncogenesis has been defined in histologically disparate varieties of sarcoma.

Adult↗
PubMed2006

Clonality analysis of pediatric multiple tumors: two case reports and laboratory investigation.

We examined the possibility of using microsatellite and mitochondrial DNA polymorphisms as markers to detect the clonal origin of tumor cells found in the same patient. We considered two children with complex tumor diseases: one with supratentorial primitive neuroectodermal tumors (PNET) and a hepatic rhabdoid tumor and another with brain and abdominal rhabdoid tumors. In the first patient we found an mtDNA cytosine insertion both in the normal tissue and in the primary tumor, whereas in the hepatic tumor we detected an insertion of 2 cytosine. In the second child, who had a constitutional mutation of hSNF5/INI-1, we identified the same mtDNA pattern both in normal tissue and in the abdominal tumor but not in the brain tumor, which presented three different mtDNA polymorphisms. Thus, we demonstrated the same clonal origin for tumors in the first patient and different clonal origins of the tumors in the second patient. At times it is very difficult to discriminate two neoplastic lesions or metastatic diseases by using only histopathologic techniques. Molecular examination of clonality is a useful tool to obtain information about the origin of synchronous and/or metachronous tumors found in the same patient.

Adult↗
PubMed1994

Genetic aberrations in human brain tumors.

Over the last decade, much has been learned about the genetic changes that occur in human neoplasia and how they contribute to the neoplastic state. Oncogenes and tumor suppressor genes have been identified, and many powerful molecular genetic techniques have emerged. Brain tumors have been intensively studied as part of this process. Specific and recurring genetic alterations have been identified and are associated with specific tumor types. In astrocytomas, for example, losses of genetic material on chromosomes 10 and 17 and amplification of the epidermal growth factor receptor gene seem important in pathogenesis, with the loss of chromosome 10 and the amplification of epidermal growth factor receptor being strongly associated with glioblastoma multiforme. Meningiomas, on the other hand, have usually lost part or all of chromosome 22. Brain tumors also express growth factors and growth factor receptors that may be important in promoting tumor growth and angiogenesis. These include epidermal growth factor, transforming growth factor-alpha, platelet-derived growth factor, the fibroblast growth factors, and vascular endothelial growth factor. In this article, we review the genetic aberrations that occur in the major types of brain tumors, including glial tumors, meningiomas, acoustic neuromas, medulloblastomas, primitive neuroectodermal tumors, and pituitary tumors. Wherever possible, clinical correlations have been made concerning the prognostic and therapeutic implications of specific aberrations. We also provide some background about the cytogenetic and molecular genetic techniques that have contributed to the description and understanding of these alterations and speculate as to some clinical and basic science issues that might be explored in the future.

Brain↗
PubMed1998

Brain tumor in the first year of life: a single institute study.

Brain tumors in infants present special diagnostic and therapeutic challenges. To figure out the clinical features, pathological classification of the tumors and the treatment outcome of infantile brain tumors, 458 children (age<16) with brain tumors were reviewed retrospectively. Among them 21 cases (4.6%) were diagnosed during the first 12 months of life. Two tumors were definitely of congenital origin. The majority of infants with brain tumors presented with increased intracranial pressure. Fourteen tumors were located at the supratentorial area. Sixteen cases had neuroepithelial tumors; astrocytoma (optic pathway), supratentorial primitive neuroectodermal tumor (PNET) and medulloblastoma were found in three cases each. There were two treatment-related mortalities. Compared with the outcomes in older children, the treatment outcome was poorer in medulloblastoma and the optic pathway glioma which showed a higher growth potential. Because of the limited application of postoperative adjuvant therapy, radical surgical removal played a more important role in this age group. The prognosis of patients in whom the tumors could not be totally removed, largely depended on the pathological malignancy of the tumors. Though the treatment outcome was not always dismal, immaturity of the brain, higher growth potential, perioperative risks, limitations in adjuvant therapy, and pessimistic attitude on the part of parents made management more challenging.

Adolescent↗
PubMed2003

[Endobronchial neurofibroma].

Neurofibroma belongs to the benign tumors and it is categorised as neuroectodermal tumor. Neurofibromas are most frequently found in the posterior mediastinum, their endobronchial localisation is rather rare. Our paper presents two cases of endobronchial neurofibromas with diverse clinical and X-ray symptomatology. Both patients underwent surgery and the etiology of tumours was assessed by histological examination of the preoperative biopsy.

Adult↗
PubMed1991

[Meningeal hemorrhage disclosing a brain tumor in a child].

The case of a 14-year-old girl who had severe subarachnoid bleeding as the first manifestation of a benign astrocytic tumor of the lateral aspect of the third ventricle is reported. Tumors that cause bleeding are usually neuroectodermal tumors in children and malignant tumors in adults. A review of the literature serves as the basis for a discussion of the frequency of bleeding as the first manifestation of brain tumors (1 to 10%) and of the pathogenesis of these hemorragies for which three theories (vascular, mechanical, and metabolic) have been put forward.

Adolescent↗
PubMed1990

[Immunohistochemical study of placental form of glutathione S-transferase in human brain tumors and fetal brains].

The activity of glutathione S-transferase placental form (GST-pi) was examined in 100 cases including various histologic subtypes and grading of human brain tumors and 10 cases of fetal brains by immunohistochemical studies. The 69% of cases with brain tumors were shown to be positive for GST-pi. This activity in neuroepithelial tumors tended to increase in order to tumor grading, however, medulloblastoma and primitive neuroectodermal tumor (PNET) were not immunoreactive with GST-pi. Embryonal carcinoma showed strong staining, although fetal brains were negative. The metastatic brain tumors showed the same reactivity with GST-pi as those of original carcinomas. Moreover, the difference of GST-pi activity was investigated on some brain tumors treated with or without antitumor drug, such as 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU). The 85% of recurrent cases showed strong staining with GST-pi, and GST-pi activity seemed to be increased after treated with ACNU. The present study indicated that GST-pi might be a useful marker for human brain tumor, as the same conclusion was applicable to other neoplastic lesions examined previously. It is suggested that the increased GST-pi activity with malignancy of tumor may indicate the tendency to recurrence. The presence of such activity in tumor cells may also imply their acquired multidrug resistance. Our findings suggest that the evaluation of GST-pi activity in brain tumors will offer a predictive value for eventual behavior of the tumor.

Biomarkers, Tumor↗
PubMed1994

The EWS gene, involved in Ewing family of tumors, malignant melanoma of soft parts and desmoplastic small round cell tumors, codes for an RNA binding protein with novel regulatory domains.

The EWS gene, which maps to band q12 of human chromosome 22, is involved in a wide variety of human solid tumors including Ewing sarcoma, related primitive neuroectodermal tumors, malignant melanoma of soft parts and desmoplastic small round cell tumors. In these tumors, the EWS is fused to genes encoding transcriptional activators/repressors, like Fli-1 or erg or ATF 1 or wt1. To better understand the function of the EWS protein, we cloned the EWS cDNA. Sequence analysis of this cDNA revealed differential splicing involving two exons encoding 72 amino acids. Both alternatively spliced transcripts, EWS and EWS-b, are expressed in a variety of cells. Because EWS proteins contain putative conserved RNA binding motifs, we studied the RNA binding properties of the EWS protein. The EWS-b protein binds to RNA in vitro and, specifically, to poly G and poly U. The RNA binding activity was localized to the carboxy terminal 86 amino acids, which constitute RGG box. Thus the amino terminal domain of EWS (NTD-EWS), which is involved in chromosome translocation may regulate the specificity of RNA binding activity of EWS. An EWS-erg chimeric protein, which is found in Ewing's sarcoma cells, functions as a transcriptional activator. Mutational analysis of EWS-erg chimeric protein revealed that NTD-EWS functions as a regulatory domain for the transcriptional activation properties of EWS-erg chimeric protein.

Amino Acid Sequence↗
PubMed1993

Ewing's sarcoma.

Ewing's sarcoma is a highly malignant tumor of uncertain origin. A strong relationship is suggested between Ewing's sarcoma and tumors of neural origin. The radiologic manifestation of Ewing's sarcoma are protean and lesions may be lytic, mixed lytic-sclerotic, or rarely, predominantly sclerotic. The lower extremity long bones are predominantly affected and most lesions are diaphyseal or metadiaphyseal. CT and particularly MR imaging are invaluable in further delineating the extent of disease not readily manifested on plain radiographs. Gallium scintigraphy and gadolinium-enhanced MR images are best for following the response to therapy. Ewing's sarcoma must be distinguished from other round cell tumors including lymphoma, neuroblastoma, and primitive neuroectodermal tumor of bone as well as from osteosarcoma.

Bone Neoplasms↗
PubMed1997

O6-Methylguanine-DNA methyltransferase protein levels in pediatric brain tumors.

Chloroethylnitrosoureas (CENUs) are commonly used in the treatment of pediatric and adult central nervous system (CNS) tumors. The antitumor activity of CENUs has been hypothesized to be due to an alkylation occurring at the O6-position of guanine in DNA. The DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) is responsible for the repair of these potentially cytotoxic lesions and may underlie tumor resistance to CENUs. The current study is the largest report of MGMT levels among newly diagnosed pediatric CNS tumors and the only study that has quantitated MGMT by both biochemical and Western immunoblot assays. Our results show a good correlation between the two methods (r = 0.66). Medulloblastoma/primitive neuroectodermal tumor and ependymoma had the highest level of MGMT, followed by high-grade glioma and low-grade glioma. These data may provide a guide to the use of CENUs in the treatment of pediatric CNS tumors.

Adolescent↗
PubMed1994

Malignant laryngeal tumors in children: a 15-year experience with four patients.

Malignant laryngeal neoplasms in children are uncommon and present diagnostic and therapeutic challenges. A 15-year retrospective review of laryngeal tumors at our institution identified four patients with malignant neoplasms. These children, 7 months to 16 years of age, were treated for squamous cell carcinoma, choriocarcinoma, rhabdomyosarcoma, and primitive neuroectodermal tumor. This report details these cases, emphasizing diagnostic approaches, treatment decisions (medical oncologic management, surgical resection), and rehabilitation measures for postlaryngectomy communication. A multi-institutional pediatric head and neck tumor registry would be a useful reference to assist with individual treatment decisions.

Adolescent↗
PubMed1994

Ewing's sarcoma--routine diagnostic utilization of MIC2 analysis: a Pediatric Oncology Group/Children's Cancer Group Intergroup Study.

Ewing's sarcoma and peripheral neuroectodermal tumor (PNET) are small blue cell tumors with no reliable positive diagnostic markers. However, Ewing's sarcoma and PNET recently have been shown to strongly express an antigen determined by the MIC2 gene, whereas other blue cell tumors of childhood for the most part do not. MIC2 analysis therefore offers a distinctive addition to the panel of immunohistochemical stains used to differentiate among small blue cell tumors of childhood, since it represents the first positive marker for Ewing's sarcoma and PNET. This study addresses the reliability of MIC2 analysis using the monoclonal antibody 12E7 on tumors registered in the current Intergroup Ewing's Sarcoma protocol. Of 244 tumors, 221 (91%) showed a diffuse strong membranous pattern. The antibody appears to withstand all the fixation variables inherent in a multi-institutional study. We conclude that MIC2 expression is highly reliable as a positive marker for the Ewing's sarcoma/PNET family of tumors when the results are interpreted in the total context with clinical and pathologic parameters.

12E7 Antigen↗
PubMed2005

Cytokeratin-positive meningeal peripheral PNET/Ewing's sarcoma of the cervical spinal cord: diagnostic value of genetic analysis.

Peripheral primitive neuroectodermal tumor (PNET)/Ewing's sarcoma (ES) of the central nervous system is extremely rare and should be differentiated from central PNET and other small blue round cell tumors. We describe a case of a meningeal peripheral PNET/ES of the spinal cord in an 11-year-old boy. Immunohistochemically, the small blue round cell tumor showed expression of epithelial markers and of CD99, thus posing an important differential diagnostic problem with a poorly differentiated synovial sarcoma. Fluorescence in situ hybridization revealed rearrangement of the EWS gene, as seen in peripheral PNET/ES. Peripheral PNET/ES does occur in the central nervous system, but its diagnosis can be extremely difficult on morphologic and immunohistochemical grounds alone. Genetic analysis plays a key role in its distinction from other small blue round cell tumors.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

[Radiologic diagnosis of malignant tumors of the pelvic bones in children].

An analysis of the data on radiodiagnosis of malignancies of pelvic bones in 50 patients, aged 10-15, is presented. Diagnosis was morphologically confirmed in all the cases: Ewing's sarcoma (41)--82%, primitive neuroectodermal tumor (6)--12% and chondrosarcoma (3)--6%. The leading clinical syndrome was pain in the loin. The significantly most frequent site was the iliac bone. X-ray imaging of tumor site and adjacent areas using standard direct, lateral and oblique projections, ultrasonography, X-ray contrast tomography, radioisotope examination, puncture and open biopsy (when indicated) proved useful.

Adolescent↗