Extreme Elevation of Carbohydrate Antigen 19-9 Linked to a Simple Biliary Cyst: A Case Report

Aims: Carbohydrate antigen (CA) 19-9 is produced by epithelial cells in the pancreas, bile ducts, stomach, colon, uterus and salivary glands. It has been shown that CA 19-9 levels are also detected high in ovarian cysts, chronic renal failure, rheumatic diseases, thyroid diseases and some lung diseases, in addition to hepato-pancreatobiliary diseases. However, it is not clearly known whether there is a relationship between very high CA 19-9 results and the presence or severity of the disease. There is no consensus in the literature on how to proceed in cases of CA 19-9 detected in screenings or coincidentally. In this case, we present the approach to a patient who was detected to have a giant cystic lesion in the liver in screenings performed due to coincidentally high CA 19-9 levels.

Presentation of Case: In the case we present, a 56-year-old female patient was found to have extremely high CA 19-9 levels (8634 U/mL) in laboratory tests performed due to chronic abdominal pain. A giant cystic lesion was detected in the liver in the imaging studies performed afterwards. Due to the pain symptoms caused by the cyst, a hepatectomy surgery was performed that included the liver segments where the cyst was found. The pathology result was found to be a “simple biliary cyst”. CA 19-9 levels decreased rapidly in the postoperative period and were observed to return to normal during follow-ups.

Discussion and Conclusion: We frequently observe that CA 19-9 is elevated in healthy individuals due to unnecessary test requests. It is known that CA 19-9 elevation associated with benign diseases has no clinical significance and does not need to be followed up. Since CA 19-9 is also known as a tumor marker, malignancy screenings or follow-up protocols are performed when high CA 19-9 levels are detected. Routine use of the CA 19-9 test as a screening tool is not recommended. However, it is beneficial to perform further examinations in patients with unexpectedly high levels.