Evaluation of Epithelial Cell Adhesion Molecule, Galectin-3, and Proliferative Cell Nuclear Antigen Expression in Thyroid Papillary Carcinomas and Their Lymph Node Metastases

Background: Thyroid papillary carcinoma (PTC) is the most common carcinoma of thyroid carcinomas and endocrine carcinomas. The diagnosis of thyroid PTC is made mainly by the presence of nuclear features such as nuclear clearing, groove, and nuclear inclusions. Some benign lesions of the thyroid may have nuclear features and growth patterns of papillary thyroid carcinomas, which can make the differential diagnosis difficult. Different immunohistochemical markers have always been needed to reduce diagnostic errors and detect malignancies in routine practice. As in all tumor cases, studies continue to understand carcinogenesis in thyroid carcinomas. One of the ways that can help understand this involves the use of new and effective immunohistochemical markers. Aim: This study aimed to examine the expression of epithelial cell adhesion molecule (EpCAM), Galectin-3 (Gal-3), and proliferative cell nuclear antigen (PCNA), which are immunohistochemical markers that may contribute to the diagnosis and prognosis of thyroid PTCs and lymph node (LN) metastases. Materials and Methods: EpCAM, Gal-3, and PCNA immunohistochemical markers were applied to 26 unifocal (UF) thyroid PTC cases and 25 thyroid PTC cases with LN metastasis or multifocal (MF) tumor field. Results: It was observed that the Gal-3 staining score decreased significantly in the LN metastasis focus compared to the UF tumor. With EpCAM significant loss of membranous expression was observed in the MF tumor compared to the UF tumor. There was no statistically significant difference between the case groups in terms of PCNA staining score. Conclusions: These results may be important in terms of obtaining new immunohistochemical clues for diagnosis and carcinogenesis in thyroid PTCs and their metastases. The number of cases in our study is limited, and we think that supporting the results with a large series of studies may contribute to the diagnosis and prognosis of the patients.