ELEVATED CA 19-9 IN AN ASYMPTOMATIC PATIENT: WHAT DOES IT MEAN?

INTRODUCTION

Carbohydrate antigen 19-9 (CA 19-9), first described in 1979, is a cell surface glycoprotein complex produced by ductal cells in the pancreas, biliary system, and epithelial cells in the stomach, colon, uterus, and salivary glands¹⁹. Its expression is only observed in patients with Lewis antigen (Le) A−B+ or Le A+B− blood groups. Up to 6% of the Caucasian and 22% of the non-Caucasian population are genotypically Le A−B− and therefore do not produce CA 19-9¹⁹.

CA 19-9 is overexpressed in many benign and malignant, gastrointestinal, and extra-gastrointestinal diseases. Its main implications are in pancreatic ductal adenocarcinoma and intraductal papillary mucinous neoplasm (IPMN), but it can also be elevated in biliary, hepatocellular, gastrointestinal, urological, pulmonary, gynecological, thyroid, and salivary gland cancers¹⁶. Benign conditions in which CA 19-9 may be elevated include pancreatitis, pancreatic cysts, diabetes mellitus, liver fibrosis, benign cholestatic diseases, and other urological, pulmonary, and gynecological diseases¹⁵.

The aim of this article was to present a case of an asymptomatic and exuberant elevation of the CA 19-9 with no identified etiology and a review of the clinical use and implications of the CA 19-9.