Diagnostic value of beta-catenin immunohistochemical staining in papillary thyroid carcinoma

Background: The gold standard of diagnosing Papillary thyroid carcinoma (PTC) is achieved through pathologic evaluation using routine hematoxylin and eosin (H and E) staining. The determination of papillary carcinoma by the histological study is mainly based on architectural changes along with nuclear clearing, overlapping, grooving, and pseudoinclusions. In the absence of these changes, papillary carcinoma is difficult to distinguish from the benign thyroid lesion (BTL). Objective: This study aimed to assess the expression of β-catenin in BTL and PTC to evaluate its diagnostic values. Materials and Methods: One hundred H&E staining slides prepared from paraffin blocks (including 48 with PTC pathology, diagnosis and 52 with BTL pathology diagnosis) that met all inclusion criteria were selected. Paraffin blocks were sectioned and stained with a β-catenin marker using the immunohistochemistry method. Data were analyzed using the SPSS (V.18). Then, the sensitivity, specificity, positive predictive value, and negative predictive value were calculated to describe the diagnostic value of β-catenin. Results: Cytoplasmic and membranous expression of the β-catenin protein was observed in 98.1% and 84.6% of BTL, respectively. Related to PTC, this record was observed in 97.9% and 93.7%, respectively. The sensitivity and specificity of cytoplasmic expression were 97.9% and 1.92%, respectively. The sensitivity and specificity of membranous expression were 93.7% and 15.3%, respectively. Conclusions: β-catenin can be used as a morpho-immunohistochemical marker to detect specific structural features such as papillae and pseudoinclusion, which are not well seen in H and E staining.