1/7. Chordoid glioma of the third ventricle: immunohistochemical and molecular genetic characterization of a novel tumor entity.Chordoid glioma of the third ventricle was recently reported as a novel tumor entity of the central nervous system with characteristic clinical and histopathological features (Brat et al., J Neuropathol Exp Neurol 57: 283-290, 1998). Here, we report on a histopathological, immunohistochemical and molecular genetic analysis of five cases of this rare neoplasm. All tumors were immunohistochemically investigated for the expression of various differentiation antigens, the proliferation marker Ki-67, and a panel of selected proto-oncogene and tumor suppressor gene products. These studies revealed a strong expression of GFAP, vimentin, and CD34. In addition, most tumors contained small fractions of neoplastic cells immunoreactive for epithelial membrane antigen, S-100 protein, or cytokeratins. The percentage of Ki-67 positive cells was generally low (<5%). All tumors showed immunoreactivity for the epidermal growth factor receptor and schwannomin/merlin. There was no nuclear accumulation of the p53, p21 (Waf-1) and Mdm2 proteins. To examine genomic alterations associated with the development of chordoid gliomas, we screened 4 tumors by comparative genomic hybridization (CGH) analysis. No chromosomal imbalances were detected. More focussed molecular genetic analyses revealed neither aberrations of the TP53 and CDKN2A tumor suppressor genes nor amplification of the EGFR, CDK4, and MDM2 proto-oncogenes. Our data strongly support the hypothesis that chordoid glioma of the third ventricle constitutes a novel tumor entity characterized by distinct morphological and immunohistochemical features, as well as a lack of chromosomal and genetic alterations commonly found in other types of gliomas or in meningiomas.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
2/7. Progressive multifocal leukoencephalopathy and gliomas in a hiv-negative patient.A case of progressive multifocal leukoencephalopathy (PML) is reported, detected at autopsy of a 30-year-old patient. The clinical picture was characterized by a progressive course of mental deterioration and ingravescent neurological symptoms. The patient was hiv-negative. He died of bronchopneumonia, after a clinical course of 13 months. autopsy disclosed pulmonary tuberculosis with involvement of regional lymph nodes. In the brain, besides numerous PML-foci of varying age and structure, a pleomorphic astrocytoma was found in the white matter of the right parietal lobe. In the brain stem glial proliferation resembling diffuse gliomatosis was also present. in situ hybridization revealed Papova-virus (JCV) in oligoglial nuclei, but not in neoplastic astrocytes. This is the third report on the concomitant occurrence of PML and glioma in man.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
3/7. Molecular genetic and proteomic analysis of synchronous malignant gliomas.Described is a patient with concurrent discrete gliomas: a pleomorphic xanthoastrocytoma with anaplastic features and an anaplastic oligoastrocytoma. The distinct and morphologically dissimilar tumors demonstrated similar genetic abnormalities by loss of heterozygosity and comparative genome hybridization. Clonality and proteomic analyses highlighted an independent origin for the two tumors. Proteomic methods may prove useful in cases where the differential diagnosis and pathogenetic origin of tumors are uncertain, as well as more globally for its ability to provide insight into specific expression of proteins that may serve as unique markers of tumorigenesis or as novel targets of therapy.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
4/7. Analysis of phenotype and genotype of individual cells in neoplasms.The authors describe a combination technique enabling detection of in situ hybridization (ISH) signals from chromosome-specific probes in interphase or mitotic cells that still retain the alkaline phosphatase antialkaline phosphatase (APAAP) or sudan black B (SBB) staining reactions (simultaneous detection) or have been first classified morphologically and then by APAAP or SBB. The technique can be used on cell suspensions, in situ cultures and tissue sections. Examples from leukemias (chronic lymphocytic, myeloid, and acute myeloid leukemia) and solid tumors (chondromyxoid fibroma and glioblastoma) illustrate the potential of the technique in investigation of cancer tissue heterogeneity. In leukemias, it can be used to study cell lineage involvement, stem cells, and minimal residual disease, as well as to monitor therapy. In solid tumors, it can be used to identify neoplastic areas of tissue and to track the site of origin of neoplastic cells. Finally, it can be used to study the significance of chromosome abnormalities in carcinogenesis.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
5/7. Rearranged p53 gene with loss of normal allele in a low-grade nonrecurrent glioma.We are studying the p53 gene profile in primary glial tumors by seeking alterations in the hybridization pattern of the tumor dna probed with a p53 gene probe. This report documents a rearranged p53 gene with loss of the normal allele in a low-grade mixed glioma which has not recurred during 4-year follow-up. The tumor had a low 5-bromodeoxyuridine (BrdU)-labeling index and low AgNOR count. The p53 protein was not detected on immunochemical staining. To our knowledge, this is the first report of an altered p53 gene in a low-grade nonrecurrent glial tumor and highlights the presence of further checks and balances on the control of cell proliferation and other malignancy-associated phenotypes, even in an already-established tumor.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
6/7. chromosomes in gliomatosis cerebri.Gliomatosis cerebri is a rare brain tumor which histologically resembles a diffuse cerebral astrocytoma. It can simultaneously infiltrate multiple sites in the cerebrum, cerebellum, brainstem, and spinal cord. This remarkable diffuseness has led to the idea that gliomatosis cerebri does not derive from a solitary focus but must arise from a broad field of glial cells. We studied the chromosomes from gliomatosis cerebri in a 12-year-old boy by conventional cytogenetics and fluorescence in situ hybridization (FISH). Aside from normal cells, we found a majority of cells with the karyotype 44,XY,del(6)(q25),del(14)(q21), der(15;21)(q10;q10),add(18)(q22),del(19)(p12),add(20)(p13),-21. A smaller proportion of cells had 88 chromosomes with a doubling of this abnormal karyotype. These findings are consistent with a clonal neoplasm stemming from a single cell. The chromosome changes we observed, with the possible exception of the chromosome 6 deletion, did not resemble those frequently found in astrocytomas. Gliomatosis cerebri may therefore belong to a separate category of brain tumors.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
7/7. Familial supernumerary chromosome and malignancy.No familial marker chromosome associated with a malignancy has been reported to date. We used fluorescence in situ hybridization (FISH) to characterize a supernumerary marker chromosome 15 ascertained during prenatal diagnosis. This supernumerary chromosome 15 was found to span three generations of a family. Three family members carrying the supernumerary chromosome 15 have also had malignancies, namely, a cystic glioma, leukemia, and thyroid cancer.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |