Abstract
The use of chemotherapy in treating malignant thyroid neoplasms with aggressive biological behavior, such as doxorubicin, has been associated with an overall poor outcome. Therefore, it has been suggested that thyroid malignant cells are resistant to apoptosis induced by chemotherapy agents. The objective of this study was to compare the immunohistochemical expression of Bcl-2 in thyroid tissues obtained from follicular hyperplasia, follicular adenoma, and follicular carcinoma of thyroid glands. This retrospective observational study was conducted at the Department of Pathology, College of Medicine, Al-Nahrain University, Baghdad, Iraq, covering the period from January 2013 to December 2023. The study focused on cases of thyroid follicular hyperplasia (20 cases), thyroid follicular adenoma (20 cases), and thyroid follicular carcinoma (12 cases) found in thyroidectomy specimens. Immunohistochemical analysis was performed on 4µm thick sections obtained from a paraffin block of tumor tissue to detect Bcl-2. Comparison of mean bcl-2 immunohistochemical score among study groups revealed that the median score was 2 in both follicular hyperplasia and follicular adenoma groups, whereas the median score was 3 in the group of follicular carcinomas, thus it was significantly higher in this later group in comparison with adenoma and hyperplasia (p <0.001). There was no significant association between Bcl-2 immunohistochemical expression and invasiveness. Bcl-2 immunohistochemical expression can be detected in follicular thyroid neoplasms with the highest intensity in carcinoma cases, suggesting a role for Bcl-2 in marinating the growth of these neoplasms, but it does not correlate with the degree of tumor invasiveness.