Cytokeratin immunostaining forms the bedrock of the immunohistochemical evaluation of
tumors. Cytokeratin 19 (CK19) belongs to a family of keratins, which are normally expressed
in the lining of the gastroenteropancreatic and hepatobiliary tracts. CK19
immunohistochemistry has been used successfully in thyroid tumors to recognize papillary
carcinomas for some time. However, its use in the pancreas, liver, and gastrointestinal tract
(GIT) has only recently come to the fore. The purpose of this review is to look at the use of …