Table 3 Predominant patterns of expression of cytokeratin 7 and cytokeratin 20 in carcinomas arising in different organs.

Immunophenotype	Organ of origin/histological type
CK7+/CK20−	Breast carcinoma
	Non‐mucinous ovarian carcinoma
	Pulmonary adenocarcinoma
	Endometrium
	Pleural mesothelioma
	Thyroid carcinoma
	Oesophageal adenocarcinoma
	Salivary gland
CK7−/CK20+	Colorectal
CK7±/CK20+	Gastric
CK7+/CK20±	Pancreas/biliary
CK7+/CK20+	Mucinous ovary
	Transitional cell
CK7−/CK20−	Prostate
	Renal clear cell carcinoma
	Hepatocellular
	Pulmonary squamous carcinoma