Cytochemical assessments of the nuclear DNA distribution pattern by means of image and flow cytometry in thyroid neoplasms and in non-neoplastic thyroid lesions. A comparative methodological study.

The two most prevalent techniques for cytochemical DNA assessment of the nuclear DNA distribution pattern in neoplastic cells are image cytometry (ICM) and flow cytometry (FCM). The aim of the present study was to compare the results of nuclear DNA assessments, obtained by means of these two methods, in fresh surgical biopsy specimens from the thyroid gland, both in neoplasms and in nonneoplastic lesions. Material for DNA analysis was taken preoperatively by fine needle aspiration (FNA) biopsy from 13 papillary thyroid carcinomas and analyzed by the two methods. Surgical specimens were taken from 48 papillary thyroid carcinomas (one of which showed low differentiated papillary and anaplastic giant cell formations at autopsy), 2 follicular carcinomas, 66 follicular adenomas, 7 medullary carcinomas as well as from the nodules of 17 non-toxic colloid goitres and 19 specimens from the diffusely hyperplastic thyroid parenchyma in patients with hyperthyroidism. For the ICM assessments, FNA biopsies or imprints were made from the macroscopically identified fresh thyroid biopsy specimens; for the FCM assessments FNA specimens from the same region were used. In 155 out of the 159 specimens the results obtained by means of the two methods were the same. The DNA distribution pattern in 106 of the neoplasms and in all the 36 non-neoplastic lesions were of the "euploid" type (i.e. "diploid" or diploid/tetraploid"), whereas that of 17 neoplasms were of the "aneuploid" type. Fifteen of the histopathologically benign follicular adenomas showed a cytochemical DNA distribution pattern that by means of FCM was of the "aneuploid" type.(ABSTRACT TRUNCATED AT 250 WORDS)