PLOIDY ANALYSIS IN PARAFFIN-EMBEDDED MALIGNANT FIBROUS HISTIOCYTOMA BY DNA CYTOFLUOROMETRY AND FLUORESCENCE IN-SITU HYBRIDIZATION

To prove the relationship between chromosomal aberration and DNA ploid y in human malignant fibrous histiocytoma (MFH), fluorescence in situ hybridization (FISH) and DNA cytofluorometry were performed in this st udy. For FISH study, the nucleus of each tumor cell was isolated from paraffin-embedded tissue of nine MFHs., Five chromosome-specific DNA p robes (1p36, 1q12, 8q21.3, 11 centromere, and 17 centromere) were hybr idized on cell nuclei. Cells with more than three probe signals were r egarded as chromosome polysomy. All of the tumors analyzed by FISH had extra copies. The average percentage of polysomy in all tumors was hi gh, ranging from 10.2% to 49.2%. The DNA ploidy patterns, and the perc entage of hyperdiploid cells showing a greater DNA content than diploi d cells, were obtained from DNA cytofluorometry. Three of nine were di ploid patterns and six were non-diploid patterns, and the percentage o f hyperdiploid cells in all tumors was high, ranging from 9.1% to 61.9 %. The percentage of polysomy could be correlated with the percentage of hyperdiploid cells in each cell. In this study, we found that the D NA ploidy change was closely correlated with aberrations of chromosome copy number in MFH. In addition, the alterations of specific chromoso me copy number could be detected in MFH showing diploid cells. Thus, t hese data indicate that FISH and DNA cytofluorometry are available as a cytogenetic tool for the analysis of interphase nuclei of bone and s oft tissue tumors including MFH. (C) 1997 Elsevier Science Ireland Ltd .