[Nuclear DNA pattern of thyroid tumor]

The nuclear DNA contents of 50 thyroid tumors were measured paraffin block samples and needle biopsies by using microscopic photometry, and the diagnostic value of this measurement was examined. Thyroid tumors included 17 papillary carcinomas, 15 follicular carcinomas and 18 benign tumors. The results confirmed the possibility of discriminating between benign and malignant tumors except in cases of follicular carcinoma with minimal invasion. This method seemed to be most valuable in the diagnosis of cases with class III FNA. A review was made of the relation between DNA content and prognostic factors, for example the degree of invasiveness of the thyroid tumor, intra-tracheal invasion, intra-thyroid metastasis and lymphatic metastasis. DNA content was increased only in cases with intra-tracheal invasion.