Significance of the "tissue microarray" technique in diagnosis and prognosis of B non Hodgkin-s lymphomas

Abstract

The novel technology of tissue microarray (TMA) allows rapid and cost-effective analysis of hundreds of markers on the same set of specimens. Limited amounts of tissue that could be analyzed and the problem of tissue heterogeneity are the major drawbacks of the TMA technique for immunohistochemical characterization of lymphomas. These problems do not outweigh the enormous advantages of TMA, namely the cost- and time-saving, and the mostly homogeneous results of immunohistochemistry. In Non Hodgkin's lymphomas (NHL), TMA detection of Oct1 and Oct2 immunoglobulin transcription factors and their coactivator BOB1 showed particularly useful in distinguishing T-cell-rich B-cell lymphomas from classical Hodgkin's disease, nodular lymphocyte predominant Hodgkin's lymphoma and plasmablastic lymphomas. Outcome prediction for subtypes of diffuse large B-cell lymphomas, using a TMA panel with CD10, Bcl-6 and MUM1, was comparable to results of cDNA microarray analysis. Detection of p53 tumor suppressor gene and Ki-67 proliferation antigen is important for the prognosis of many NHL subtypes. In spite of their heterogeneity in expression, TMA showed 90 and 92% concordance rate, with conventional tissue sections for p53 and Ki-67 respectively, and that could be sufficient for routine practice. There is no doubt that the widespread use of TMAs will become an integral part of daily practice in research and routine clinical laboratories.