Nuclear DNA in anaplastic thyroid carcinoma with a differentiated component.

Fifteen cases of anaplastic thyroid carcinoma, including eight cases with a differentiated component, were studied by DNA analysis. All areas of anaplastic carcinoma showed an aneuploid DNA content. The eight cases of anaplastic carcinoma with differentiated component (two follicular carcinomas, two papillary carcinomas, one Hürthle cell carcinoma and three poorly differentiated carcinomas) exhibited aneuploid DNA content in the differentiated area of the tumour. Karyometric parameters allowed a fairly clear separation between giant cell, spindle cell and differentiated components. The results support the hypothesis that patients with aneuploid differentiated carcinoma represent a higher risk group and are probably more prone to developing anaplastic carcinoma.