An extremely increased CA19-9 level due to common bile duct stone: a case report

Serum carbohydrate antigen 19-9 (CA19-9), a common tumor marker, is frequently increased in bile duct malignancy. We reported a case with an extremely increased CA19-9 level due to benign common bile duct stones and gallstones. A 63-year-old male presented with intermittent right upper quadrant abdominal pain for 1 year. Tumor markers showed that CA19-9 level was more than 1,000.0 U/mL (normal range: 0–37 U/mL), CA-50 level was 466.34 IU/mL (normal range: 0–25 IU/mL), and CA24-2 level was more than 200 IU/mL (normal range: 0–20 IU/mL). Abdominal CT scan and magnetic resonance cholangiopancreatography (MRCP) demonstrated multiple stones located in the lower segment of common bile duct, lower bile duct obstruction, and gallbladder stones. Pancreatic cancer and cholangiocarcinoma were excluded. On the third day after endoscopic retrograde cholangiopancreatography (ERCP), CA19-9 level dropped to 78.62 U/mL. In conclusion, an extremely increased CA19-9 level might be observed in some patients with benign bile duct diseases.