ABSTRACT
Chromosomal abnormalities leading to altered expression and dysregulated function of genes, which are critically involved in normal cell growth and differentiation, are a hallmark of cancer cells. The importance of specific cytogenetic aberrations has been particularly evident in acute leukemias, where the identification of chromosomal abnormalities has contributed to the understanding of leukemia cell biology and the establishment of a prognostically as well as a clinically relevant classification of the disease. In recent years, considerable progress has also been made in the cytogenetic and molecular genetic investigation of lymphoproliferative disorders, and most investigators believe that almost every case is characterized by a chromosomally abnormal clone. This is also true for multiple myeloma (MM),1 although cytogenetic studies of MM cells are often hampered by the low mitotic rate of the myelomatous clone. For this reason, use of molecular cytogenetic techniques, which do not necessarily depend on dividing cells, has greatly enhanced our possibilities to investigate MM and monoclonal gammopathy of undetermined significance (MGUS) at the cytogenetic level and to derive clinically relevant information from these studies.
