A brain lesion showing EMA positivity and CEA negativity most strongly suggests a metastasis from which organ?

A brain lesion showing EMA positivity and CEA negativity most strongly suggests a metastasis from which organ?

• A. Lung
• B. Liver
• C. Brain
• D. Kidney

Answer: (D)

Immunohistochemical profiles help pinpoint the tumor’s tissue of origin. EMA is an epithelial marker seen in many carcinomas, confirming epithelial nature, while CEA is commonly expressed in adenocarcinomas of the GI tract (and some other sites). A brain metastasis that is EMA-positive but CEA-negative argues against a GI/colorectal source and is most consistent with renal cell carcinoma, which often shows EMA positivity and lacks CEA expression. Among the given options, that profile best fits a metastasis from the kidney.

Immunohistochemical profiles help pinpoint the tumor’s tissue of origin. EMA is an epithelial marker seen in many carcinomas, confirming epithelial nature, while CEA is commonly expressed in adenocarcinomas of the GI tract (and some other sites). A brain metastasis that is EMA-positive but CEA-negative argues against a GI/colorectal source and is most consistent with renal cell carcinoma, which often shows EMA positivity and lacks CEA expression. Among the given options, that profile best fits a metastasis from the kidney.