A Significant Increase in the Serum Carbohydrate Antigen 19-9 Level Accompanied by Acute Cholecystitis and Choledocholithiasis: A Case Report and Review of the Literature.

An 80-year-old man with jaundice and fatigue was referred to our hospital. A laboratory examination revealed increased levels of hepatobiliary enzymes, and CA19-9 levels increased to 29,512 U/mL. Based on the findings of imaging examination and laboratory data, the patient was diagnosed with acute cholecystitis and choledocholithiasis. The possibility of malignancy could not be ruled out because of the high levels of CA19-9. Antibiotic administration was commenced, and the common bile duct stone was endoscopically removed. One month after treatment, the CA19-9 level decreased to within the normal range. One year after treatment, imaging examinations did not reveal any malignancy.