Unknown Primary

Question 1

What are the CK immunostains for colorectal cancer? Other tumors with a similar molecular profile?

Answer 1

CK 20+, CK7-, CDX2+
Other tumors: Merkel cell carcinoma, small intestine, appendix

Question 2

What are the CK markers for lung adeno cancer?

Answer 2

CK7+, CK20-
Other tumors: adrenocortical, hepatocellular, non seminoma germ tumor, small cell lung, prostate, renal cell, squamous cell (including lung and esophagus), head/neck squamous

Question 3

What is the staining for ovarian cancer?

Answer 3

Mucinous carcinoma: CK7+, CK20 +/-
Serous carcinoma: CK7+, CK20-, PAX8+, WT1+. The presence of Mesothelin suggest a ovarian primary or primary peritoneal dx