Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc
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Comparative Study
Determination of Her-2/Neu status in breast carcinoma: comparative analysis of immunohistochemistry and fluorescent in situ hybridization.
Her-2/neu (H2N) status in breast carcinoma has been considered a prognostic factor that may have therapeutic implications; however, the correlation between H2N overexpression and gene amplification has not been completely defined. A consecutive series of ductal carcinomas (34 invasive and 7 in situ) were analyzed by fluorescent in situ hybridization for H2N gene and chromosome 17 copy number using touch preps of intact cells and by immunohistochemistry, using three different commercial antibodies to H2N protein (Zymed, clone 31G7; Ventana, clone CB11; and Dako, polyclonal) in corresponding formalin-fixed, paraffin-embedded tissue sections. Gene amplification was classified as unequivocal if more than five signals were present in more than 80% of the counted nuclei and absent if more than 80% of the nuclei counted contained two or fewer gene copies. ⋯ Discordance between H2N and chromosome 17 copy number was not a useful means of defining amplification. Two cases of ductal carcinoma in situ with the Zymed antibody and two with the Dako antibody showed 3+ staining despite lack of unequivocal gene amplification. We conclude that (1) strong H2N immunostaining is highly associated with gene amplification, although there is minor variation in sensitivity between different antibodies; (2) a subset of breast carcinomas (3 to 15%) demonstrate moderate H2N staining without evidence of amplification, and it is unclear whether they represent highly sensitive staining or are a subset of cases that show overexpression without amplification; (3) gene amplification, as detected by fluorescent in situ hybridization, is associated with at least 10 gene copies per nucleus, and lower gene copy duplication (3 to 4/nucleus) is frequent, usually the result of chromosome 17 polysomy, and not associated with high-level overexpression; (5) overexpression of H2N without amplification may be more frequent in ductal carcinoma in situ, implying a different role in the biology of preinvasive versus invasive neoplasm.
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Stromal extracellular matrix (ECM) components are thought to play an important role in regulating invasion of human gliomas. Macrophages and microglial cells may heavily influence the integrity of the extracellular compartment of gliomas, and the affected ECM may play a key role in regulating migratory activity of both tumor cells and macrophages/microglia. The aim of this investigation was to study immunohistochemically the expression patterns of four ECM components: fibronectin, laminin, collagen IV, and tenascin (TN) in human gliomas, with special attention to TN. ⋯ In addition, we saw a morphologically spatial correlation between higher densities of macrophagic/microglial infiltration and TN expression in perinecrotic areas in glioblastomas. Attachment of macrophages to TN-positive basement membrane zones of newly formed stromal blood vessels was evident. On the basis of our results, we conclude that TN may play a crucial role in regulating trafficking of cells of monocyte lineage in human gliomas.