AdenoCA of Colon : Immunostains - CK20

With rare exceptions, colorectal carcinomas are CK20 positive and CK7 negative. This pattern helps distinguish them for lung and ovarian carcinomas which tend to be CK20 negative and CK7 positive. CK7 positivity has been reported in rare cases of poorly-differentiated colorectal carcinomas.

The image shows CK20 positivity in metastatic pelvic floor deposits in a case of colorectal carcinoma.