2999 Is There Truth to the Numbers?

Abstract

INTRODUCTION: CA 19-9 is a tumor marker associated with pancreatic and biliary tumors that can be directly measured in the blood with a normal range of 0-37 units/mL. Other inflammatory conditions such as biliary obstruction can also cause an elevation, which can obfuscate the diagnostic and prognostic value of CA 19-9. CASE DESCRIPTION/METHODS: A 66-year-old male with no medical history presented with a 1-month history of abdominal pain, jaundice, and weight loss. He was febrile at 100.4 F. Bilateral conjunctival icterus, full upper body jaundice, hepatomegaly, and mild tenderness to deep palpation in the right upper quadrant and epigastric regions were noted on exam. Gallbladder ultrasound revealed significant common bile and intrahepatic duct dilation concerning for obstructive lesion with no gallstones and minimal sludge. Total bilirubin was 27 mg/dL. CA 19-9 was elevated at 9,272 units/mL. CT abdomen and pelvis with contrast confirmed severe common bile and intrahepatic duct dilation with CBD measuring up to 22 mm. MRCP revealed marked intrahepatic and extrahepatic biliary dilation with dilated CBD up to 24 mm and choledocholithiasis with the largest gallstone measuring 15 mm in the distal CBD. ERCP revealed CBD stricture and sphincterotomy was performed with temporary stent placement. Ceftriaxone and metronidazole were given for ascending cholangitis. Fine needle aspiration was done by EUS, which was negative for malignancy on pathology. Repeat MRCP showed improvement in dilation and CBD now at 14 mm. Repeat CA 19-9 was 193 units/mL. Of note, CT chest with contrast did not reveal any evidence of pulmonary metastasis, CEA level was normal, and hepatitis panel was negative. DISCUSSION: A CA 19-9 cutoff of greater or equal to 300 unit/mL have been reported to have a specificity of 87% for cancer in patients with cholangitis. However, an extremely elevated CA 19-9 level does not always equal cancer or correlate with tumor burden and should not be used as the sole criterion for a diagnosis of malignancy. Non-cancerous causes of elevated CA 19-9 include gallstones, cholangitis, bile duct obstruction, and pancreatitis. EUS was critical in obtaining tissue to exclude pancreatic and biliary cancer. CA 19-9 and total bilirubin levels dropped after CBD stent placement, supporting a diagnosis of cholangitis without tumor. This is a rare case of extreme tumor marker elevation caused by choledocholithiasis and cholangitis, which serve as a cautionary tale of not relying too heavily on numbers to treat the patient.