Thyroid lesion can be diagnosed using histopathological criteria which allows us to differentiate between benign and malignant lesion but in some cases suspicious areas were noted in few foci.in such cases immunohistochemistry (IHC) is used to differentiate between benign and malignant lesion. Panel of two marker, Ck-19 and TPO increases the diagnostic accuracy in the thyroid lesion than a single marker.
Aim: To analyze the IHC expression of TPO and CK 19 in both benign and malignant thyroid nodular lesions.
Material and Methods: Prospective observational study of 100 thyroid specimens was studied for detailed histopathological examination and expression of immunohistochemical markers thyroid peroxidase and cytokeratin-19.
Results: TPO IHC marker was expressed by all benign and non-neoplastic lesion of thyroid and absent in case of malignant lesions. While CK-19 was expressed in all malignant thyroid lesion and shows focal and weak staining in noted in benign lesions.
Conclusion: A combination of positive and negative markers is essential in distinguishing benign and malignant thyroid lesion. TPO expression indicates benign condition and loss of its expression implicates malignant transformation and strong membranous ck-19 indicates malignancy.