The diagnostic value of flow cytometric DNA measurements in selected disorders of the human thyroid.

A flow cytometric (FCM) analysis of biopsies from 19 patients with thyroid lesions (Hashimoto's thyroiditis, hyperplastic goiter, colloid and adenomatous nodular goiter, follicular adenoma, follicular carcinoma, anaplastic carcinoma) was performed to evaluate the relevance of such results for the individual diagnosis and prognosis and prognosis of such diseases. All cases of Hashimoto's thyroiditis, the colloid nodular goiters, and the hyperplastic goiter had a unimodal diploid pattern, while the anaplastic carcinomas were aneuploid. These lesions are, however, easily diagnosed on morphological grounds and their FCM classification would only be redundant. Follicular adenomas and follicular carcinomas may be either unimodal diploid or aneuploid, and our single case of adenomatous colloid goiter showed a bimodal DNA distribution. This means that a diploid modal DNA content in a follicular tumor does not rule out malignancy, while aneuploidy is not an unequivocal sign on malignancy. The evaluation of the percentage of cells in S-phase did not seem to contribute valuable information for the individual diagnosis of malignancy within the group of thyroid lesions studied. Our study indicates a rather limited clinical value of FCM measurements of DNA in the individual case of thyroid disease.