Simultaneous fluorescence immunophenotyping and interphase cytogenetics: a contribution to the characterization of tumor cells.

In immunocytochemical studies, the phenotypic evaluation of tumor cells is often complicated by accompanying normal cells, representing the original tissue or infiltrating leukocytes. This holds particularly true for tissues with a great morphological and immunophenotypical variability, such as bone marrow. A method that identifies mitotic tumor cells by chromosomal aberrations and permits the subsequent immunophenotypical analysis was a first progress, demonstrated by Teerenhovi et al. However, the results are usually hampered by the low number of analyzable mitoses. We demonstrate here a method that simultaneously combines immunophenotyping and in situ hybridization with centromere-specific probes. Using our method, numerically aberrant tumor cells can be identified by interphase cytogenetics and subsequently analyzed immunophenotypically. Since all interphase cells can be analyzed, we are not limited by the number and banding quality of analyzable mitoses.