[Investigation of practical application of fluorescence in situ hybridization (FISH) analysis using microwave irradiation in formalin-fixed, paraffin-embedded tissue sections].

We investigated fluorescence in situ hybridization (FISH) analysis using microwave irradiation in formalin-fixed, paraffin-embedded tissue sections of breast fibroadenoma. Higher percentage of cells with 2 signal copies of chromosome 3 centromere could be obtained in the condition of 5 microns thick sections, when we counted cells of more than 4 microns of nuclei in thickness. This method showed about the same results as FISH using cells separated from the same tissues. Percentage of cells with 2 signal copies of chromosome 17 centromere in 14 cases was 80.6 +/- 4.0% (Mean +/- S.D.). This method is expected in the application of the prognosis estimation of the breast cancer.