Comparison of nuclear DNA content in locally invasive and noninvasive papillary carcinoma of the thyroid gland

Extrathyroidal invasion of papillary carcinoma of the thyroid gland has a very bad prognosis. A retrospective study was performed on 40 specimens from patients with papillary carcinoma of the thyroid gland to find out whether DNA ploidy correlated with aggressive tumor behavior. The nuclear DNA content of 20 locally aggressive papillary thyroid carcinomas was studied by flow cytometry. The results were compared with those of a matched control group of 20 patients with noninvasive papillary tumors. Forty percent of the tumors with spread to extrathyroid tissue were aneuploid, whereas all the tumors without such extension were diploid. This difference was statistically significant (p < 0.003). The data suggest that the differentiation of locally noninvasive and invasive papillary thyroid carcinomas may be potentially possible by nuclear DNA determination.