A Case of Cholangiocarcinoma with Markedly Elevated Serum CA199 as the Initial Symptom

This report presents a case of intrahepatic cholangiocarcinoma (ICC) initially manifested by a significant elevation of serum CA199. The patient, a middle-aged male with a history of hypertension, renal disease, and renal transplantation, exhibited no typical clinical symptoms but was found to have a persistently elevated CA199 level during follow-up (from 218.6 U/mL to 4000 U/mL). Early imaging studies showed no obvious signs of tumor, but subsequent MRI revealed a nodule in the left lobe of the liver. Postoperative pathology confirmed moderately differentiated cholangiocarcinoma (pathological stage IA). The CA199 level significantly decreased after surgery and gradually returned to normal. This case suggests that persistent isolated elevation of CA199 may be an important indicator of early cholangiocarcinoma, and malignancy should be highly suspected, especially after excluding false positives. Combining imaging and pathological examinations is crucial for the early detection of cholangiocarcinoma, which can effectively improve patient prognosis.