CEA, pancreatic Cyst Fluid

Carcinoembryonic antigen (CEA), a 180 kD intracellular adhesion molecule expressed in high concentrations in the fetus but normally not found in adult serum because the synthesis of this protein ceases after birth. However, it reappears in a high concentration in the sera of patients with colorectal (57%), gastric(41%), hepatocellular(45%), pancreatic(59%) and biliary(59%) carcinoma. Pancreatic cysts are increasingly recognized as a dilemma in clinical practice because of their uncertain risk of malignancy. Various tumor markers (i.e. CA 19-9, amylase) have been evaluated to distinguish nonmucinous, nonmalignant pancreatic cysts from mucinous cysts, which have a high likelihood of malignancy. Carcinoembryonic antigen (CEA) has been found to be the most reliable tumor marker for identifying those pancreatic cysts that are likely mucinous. In cyst aspirates, CEA concentrations > or =200 ng/mL are highly suspicious for mucinous cysts. When the concentration of CEA in cyst fluid is higher, there is a greater chances that the mucinous cyst is malignant. However, CEA testing does not reliably distinguish between benign, premalignant, or malignant mucinous cysts. CEA test results should be therefore correlated with the results of imaging studies, cytology, other cyst fluid tumor markers (i.e, amylase, lipase, CA 15-3, CA 72-4 and CA 19-9), and clinical findings for diagnosis.