A Comparative Study of DNA Cytometry Methods for Benign and Malignant Thyroid Tissue

Abstract
DNA measurements of 46 thyroid specimens were performed by use of fresh tissue for flow cytometry and formalin-fixed paraffin-embedded tissue for flow and static cytometry. The tissue included four histopathologic subgroups, i.e., 19 colloid goiters, 7 papillary carcinomas, 10 follicular adenomas, and 10 follicular carcinomas. The methods measured DNA index and the percentage of cells in S-phase for each subgroup. There was a strong correlation between the methods for DNA-index measurements. In three cases, tissue interpreted as diploid by one method was aneuploid by another method. The S-phase measurements were not reproducible between the methods because of the low percentage of cells in S-phase (mean: 2.6%; range: 0.0–7.5% overall). Aneuploid cells were rare in nodular goiter (2 of 19 cases, 10.5%) but were increasingly present in subsequent subgroups, i.e., 2 of 7 papillary carcinomas (28%), 3 of 10 follicular adenomas (30%), and 6 of 10 follicular carcinomas (60%).