Diagnostic value of CD56 and nm23 markers in papillary thyroid carcinoma

Thyroid cancer is the most common malignant endocrine tumor. Nowadays tissue biopsy and pathological assessment are the best diagnostic modalities for thyroid lesions. Differential diagnosis between adenomas and follicular variant of papillary thyroid carcinoma (PTC) is an important issue in pathology.

This study is designed to show any association between expressions of CD56 and nm23 and types of thyroid lesions (benign vs. malignant).

In this cross-sectional study, 78 paraffin-embedded tissue blocks of thyroid tissue from a tertiary care center were selected, and assessed by using immunohistochemistry for expressions of CD56 and nm23 genes.

we studied 39 benign and 39 malignant thyroid lesions, CD56 and nm23 expressions were determined by immunohistochemical staining, and the results were used for differentiation of benign and malignant lesions of thyroid.

The obtained results were analyzed and evaluated using SPSS (Version 18).

CD56 was expressed in 93% of benign specimens and in only 5% of malignant types. The sensitivity and specificity of this test were 94.8% and 92.3, respectively (P = 0.001). All malignant specimens and 95% of benign specimens were positive for nm23. The sensitivity and specificity of nm23 were 100% and 5%, respectively.

Considering high sensitivity and specificity of CD56, it is possible to apply immunohistochemistry for definite diagnosis and differentiation of benign lesions from PTC. We conclude that by using this marker, the diagnostic mistakes in pathologic diagnosis of thyroid cancer versus benign lesions like thyroid adenoma will decrease.