Cytogenetics Analysis

The establishment of reliable and meaningful chromosomal (cytogenetic, karyotypic) changes in hematological disorders, primarily the leukemias and lymphomas, must be based on the examination of the involved cells or tissues. Thus, in the case of the leukemias bone marrow (BM) aspirations yield optimal results in the preponderant number of patients, whereas in the lymphomas affected tissues, usually lymph nodes, are the best source of cells carrying cytogenetic anomalies. Generally, BM is not a good source of cells for cytogenetic analysis in lymphoma. Not only is the marrow often not affected by the lymphoma, but also when it is, the number of abnormal cells is relatively small and/or the abnormal cells are not in division and, hence, do not yield a sufficient number of metaphases for cytogenetic analysis. In some situations, blood cells can be utilized as a source of metaphases affected by karyotypic changes, e.g., in cases with about 10% immature cells in the peripheral blood (PB), in chronic lymphocytic leukemia (CLL), in cases where the marrow is fibrotic or extremely hypocellular, or in determining the presence of Ph+cells in established cases of chronic myelocytic leukemia (CML) (1 ,2 ).