Test Details: Immunohistochemical testing is carried out on biopsy/resected tissue specimen. This testing helps to identify specific antigens (proteins) within tissue sections utilizing an antigen-specific antibody .Cytokeratin 19 is a type I cytokeratin and the smallest human cytokeratin found in both simple and complex epithelium. It is positive in Adenocarcinoma of the lung, gastrointestinal tract, pancreas and biliary tract, breast, endometrium; transitional cell carcinoma, Neuroendocrine tumours, papillary thyroid carcinoma, mesothelioma.