Diagnostic Values of CD56 Marker in Differentiating Papillary Thyroid Carcinoma from Benign Follicular Lesions

Abstract

Thyroid cancer is the most common malignancy in the endocrine system. Occasionally, the distinguishing of malignant tumors from benign lesions may be diff icult through histological evaluation. Nowadays, Ancillary assays such as immunohistochemistry are used for this purpose. The present study was conducted to evaluate the CD56 diagnostic value in distinguishing benign cases from malignant thyroid tumors. The paraff in blocks of patients with a pathologic diagnosis of benign lesions and papillary thyroid carcinoma were included. The f indings from the histological evaluation were compared to the CD56 immunohistochemistry results. Anti-CD56 monoclonal antibodieswereused forimmunohisto-chemically staining. Less than 10% staining was considered negative. CD56 marker was positive in 20% of patients with thyroid malignancy. The marker positivity in the benign lesionswas signif icantly higherthan thosewith thyroid malignancy i.e., the 100% of patients with benign thyroid lesions showed a high expression of CD56. The Sensitivity and specif icity of CD56 marker in distinguishing non-malignant from malignant lesionswere100% and 80%, respectively.