[Immunomorphological characteristics of the infiltrative growth in well differentiated thyroid carcinoma].

An immunomorphological study of 52 samples of normal thyroid tissue, 10 adenomas, 42 well differentiated carcinomas and 2 metastases has been performed using markers of the epithelium, extracellular matrix and angiogenesis. Basal keratin N 17 of the compound epithelium occurred only in malignant tumors. The highest number of the keratin N 17-positive cells was registered in sclerosing A-cell cancer, medullary and mixed C-cell cancer which is very aggressive. These cells locate in the foci of proliferation of tumor structures and in the regions of infiltrative growth. Multiple defects of basal membranes and prevalence of capillaries marked by antibodies to CD-31 over those identified by the antibodies to factor VIII were found in the areas of strong expression of keratin 17. Thus, the above markers detect foci of aggressive growth even in well differentiated thyroid carcinomas. This fact may be of prognostic value in oncomorphological practice.