[Morphologic and molecular-genetic characteristics of carcinoma, adenoma and surrounding tissue of the thyroid gland].

The majority of thyroid tumors are not homogeneous histologically, this creating difficulties in interpretation of different carcinoma variants. The aim of the study was a complex comparative study of morphogenetic changes in carcinoma, adenoma and surrounding thyroid tissue. Surgical material from 48 patients operated because of nodular (multinodular) euthyroid goiter in Moscow Medical Academy in 1990-1997 was used. It was established that all the observations of early thyroid carcinoma diagnosed clinically as a nodular (multinodular) euthyroid goiter were represented by differentiated forms of thyroid carcinoma. Thyroid carcinoma was characterized by higher values of biomolecular markers as compared to adenomas and surrounding tissue. High values of c-myc expression in adenomas and surrounding tissue may indicate possible genetic rearrangements. A peculiar feature of carcinomas was the fact that deletions and replication errors in malignant tumors in this study were found simultaneously in the three genes investigated. As to different histological types of carcinoma, the most frequent deletions of the genes studied were observed in medullary and papillary-follicular carcinoma. High values of heterozygosity loss were found already in adenomas and surrounding tissues, this indicating the presence of the genetic changes already in the benign tumors and surrounding tissue.