European Journal of Cardiovascular Medicine

Background: Papillary carcinoma of the thyroid(PTC) is the most common malignant thyroid carcinoma. Histological diagnosisof PTC is generally easy in majority of cases, because of its diagnostic clue that is presence of its characteristic nuclear feature. Due to its tumourheterogeneity, it is difficult to distinguish papillary carcinoma thyroid from thyroid papillary hyperplasia, solitary nodules with papillary transformation and follicular variant from other follicular thyroid lesions. As a result, immunohistochemistry(IHC) plays a supplementary role in the effort to resolve such dilemma. The study aims to evaluate the role of CK19 and CD 56 as supplementary diagnostic markers in diagnosis of papillary carcinoma thyroid. Methodology: Observational study was conducted by light microscopy and immunohistochemical examination of 150 thyroidectomy specimens at department of pathology studied in teritiary care hospital over a period of 2years Oct 2019 to Sept 2021. Results: Out of the 150 patients, 138(92%) were females and 12(8%) were males. In present study, majority of the thyroid lesions occurred between the age groups 31-40 years (31.33%) followed by 41-50 years (26%). 30 cases are subjected for CK19 and CD56 IHC.  CK 19 staining reveals strong positive expression in 9 cases,which include Classic variant of PTC(2cases),follicular variant of PTC(3cases),undifferentiated thyroid carcinoma(1 case) and multinodular goitre with suspicious papillary carcinoma like areas(2 cases).Lack of CD56 expression (negative) is seen in 10 cases. out of which 8 cases of malignant thyroid lesions - PTC- classic variant(2cases), PTC-follicular variant(3cases), multinodular goiter with microcarcinoma (2cases), undifferentiated thyroid carcinoma(1case) show negative CD56 expression.Conclusion: Classical papillary thyroid carcinoma has typical features on histopathology and does not need any additional Immunohistochemistry markers.  IHC helps to differentiate PTC and its variants from other mimicking thyroid lesions to sub classify them accurately.