Table 1.

Main primary origins of carcinomas of unknown primary site (CUPs) based on staining for CK7 and CK20 [4,8].

CK7+/CK20−	CK7+/CK20+	CK7−/CK20+	CK7−/CK20−
Breast carcinoma Lung adenocarcinoma Endometrial adenocarcinoma Endocervical adenocarcinoma Ovarian (serous) carcinoma Cholangiocarcinoma Small cell lung carcinoma Mesothelioma Thyroid carcinoma Salivary gland tumours Kidney (papillary) Urothelial carcinoma (subset) Pancreatic adenocarcinoma Gastric adenocarcinoma	Urothelial carcinoma Pancreatic adenocarcinoma Ovarian mucinous carcinoma Bladder adenocarcinoma Gastric adenocarcinoma Cholangiocarcinoma	Colorectal adenocarcinoma Merkel cell carcinoma Gastric adenocarcinoma	Prostate adenocarcinoma Renal (clear cells) Hepatocellular carcinoma Adrenocortical carcinoma Non-seminoma germ cell tumours Mesothelioma Small cell lung carcinoma Gastric adenocarcinoma