PREVALENCE OF MUTANT BRAF<sup>V600E</sup> IN THE PAPILLARY THYRoiD CARCINoMA IN PATIENTS FROM KAZAKHSTAN AND ITS CORRELATION WITH CLINICAL-MORPHOLOGICAL TUMOR CHARACTERISTIC
The BRAFV600E mutation is the most frequent somatic oncogenic event in adult patients with papillary thyroid carcinoma (PTC). This work set out to determine the prevalence of mutant BRAF and its correlations with clinical-morphological characteristics of PTC, and to examine feasibility of detection of BRAFV600E in fine-needle aspiration biopsy material in patients from Kazakhstan. A total of 92 consequent patients diagnosed and treated for PTC from January 2016 to July 2017 were enrolled. Serial tissue sections of formalin-fixed paraffin embedded tissues were stained with hematoxylin and eosin, and immunohistochemically with monoclonal antibodies specific to the BRAFV600E protein. Positive immunohistochemical reaction was registered in 67.4 % of cases.