Markedly Elevated CA 19-9 in a Case of Mirizzi’s Syndrome: An Atypical Presentation

Abstract

Introduction: The CA 19-9 antigen is commonly used as a tumor marker for malignancies of the pancreas and biliary tract. It has been suggested that high levels of CA 19-9 (>300 U/mL) have a strong correlation with malignant biliary pathology. In this case report, we present a patient with exceptionally elevated levels of tumor marker (CA 19-9 >4000 U/mL) in the setting of Mirizzi’s syndrome. Case Report: A 51-year-old male with a several week history of epigastric pain presented to the emergency department with new onset jaundice, tea-colored urine, and light stools of 1-week duration. Total bilirubin was elevated at 19.6 mg/dL. Initial abdominal CT scan revealed markedly dilated intrahepatic and common bile ducts, the latter measuring 1.5 cm. No stones or masses were visualized. CA 19-9 levels were elevated at 4258 U/mL. Given his presentation, clinical suspicion was high for a biliary tract malignancy, specifically early pancreatic cancer or a lesion at the ampulla of Vater. The patient underwent endoscopic ultrasound examination demonstrating a large stone at the junction of the cystic duct and common bile duct with a markedly enlarged gallbladder concerning for Mirizzi’s syndrome with impending hydrops. ERCP was performed with occlusion cholangiogram and balloon sweep of the bile duct without evidence of stones. The wire was advanced into the cystic duct with contrast injected to confirm the large stone at the junction of the bile duct and cystic duct. Maneuvers to remove the stone were unsuccessful. A stent was placed in the bile duct to achieve adequate drainage upstream from the obstruction. The magnitude of the stone was such that subsequent cholangiogram did not demonstrate cystic duct filling beyond the level of obstruction. The patient subsequently underwent percutaneous cholecystostomy tube placement and was continued on antibiotics. He improved clinically with gradual decrease of his hyperbilirubinemia and underwent a laparoscopic cholecystectomy four weeks later with normalization of his CA 19-9 level and liver-associated tests. Discussion: There is a growing body of data that demonstrates elevated levels of CA 19-9 in benign biliary pathology. To our knowledge, there are only 3 other reports of CA 19-9 elevations of this magnitude secondary to Mirizzi’s syndrome. EUS as a diagnostic tool was not mentioned in any of these reports and diagnosis was discovered intraoperatively during cholecystectomy or, in one case, laparotomy for open liver biopsy. EUS can be a useful tool to evaluate for gallstones impinging on the common bile duct to further distinguish between malignant etiology and Mirizzi’s syndrome, which can be difficult to visualize with other imaging modalities. Disclosure - Dr. Shah - Speakers Bureau: US Endoscopy.