Background: Papillary thyroid carcinoma (PTC)is the most common form of thyroid cancer, however, it is often difficult to differentiate PTC from benign papillary hyperplasia of the thyroid gland based on their morphology. Immunohistochemical markers can decrease the diagnostic dilemma, effectively pointing out cases with more chance of becoming malignant.

The objective of my study is to understand the utility of cytokeratin-19 and Galectin-3 in the diagnosis of papillary thyroid carcinoma

Method: A total of 54 samples from benign group and 54 samples from histopathologically proven papillary thyroid carcinoma were collected. Histomorphological features and their immunohistochemical expression of CK-19 and Galectin-3 were studied. Data thus obtained was analysed using software SPSS version17.0. Histopathological diagnosis was considered as the gold standard.

Results and Discussion: The 108 thyroid samples were diagnosed as follows; 30 Cases of multinodular goiter, 24 case of follicular adenoma, 19 cases of PTC classic variant, 17cases of follicular variant of papillary carcinoma, 17 cases of other variants of papillary thyroid carcinoma. Sensitivity, specificity and diagnostic accuracy of CK-19 being 94.4 %, 50% and 72.2%. respectively with a kappa value 0.481 .Positive predictive value of CK-19 was found to be 67.1% and negative predictive value of 84.4%. Sensitivity, specificity and diagnostic accuracy of Gal-3 being 72.2% 90.7% and 81.5% respectively with a kappa value 0.630. Positive predictive value was found to be 88.6% and negative predictive value was found to be 76.6%.By combined immunostaining of CK-19 and Gal-3 96.3% malignant nodules could be identified and 51.9% of benign nodules could be differentiated correctly.

Conclusion: In this study CK-19 was more sensitive while Galectin-3 was found to be more specific. when combined the sensitivity has increased to 96.3%.So if we use a panel of markers including CK-19 and galectin-3,it would help to pick out more cases of Papillary thyroid carcinoma so that early treatment can be given to such patients

Keywords: Immunohistochemistry; Galectin-3; CK-19; follicular adenoma; Multinodular Goiter; papillary thyroid carcinoma.

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Dr C.S. Sakunthala Bhai

Professor and Head of the Department, Department of Pathology, Jubilee mission Medical College & RI