Objective: The aim of this study is evaluate benign and malignant thyroid lesions and evaluate the contribution of various diagnostic immunohistochemical markers such as CK19, HBME1, CITED1 and Galectin3.

Material and Method: This retrospective study includes 121 cases which were diagnosed as FA, FC, PC and AN/HN. Cases were reviewed again and immunohistochemical markers were studied by the suitable paraffin blocks. By the staining of the lesion, 10% and upper levels of expression were accepted as positive. In addition, the intensity of the expression was interpreted in three degrees (mild-moderate-strong). The results were evaluated statistically. Pearson Chi-square test was used to compare qualitative data. Significance level was taken as p <0,05.

Results: The positive and negative expression rates demonstrated by immunohistochemical markers and the comparative results are shown at the tables.

Conclusion: In the differentiation of benign and malignant lesions of the thyroid, these three immunohistochemical markers other than CITED1 should be used. It was concluded that three markers except CITED1 were particularly useful in the differentiation of benign and malignant. Other results are given in the conclusion of the article.