Do All Fingers Point Towards Malignancy? Story of a Great Masquerader

Abstract

Purpose: A 49-year-old man presented with dark urine, epigastric discomfort, and 20-pound weight loss in 3 months. Past medical and family history was unremarkable. He denied alcohol use. On examination, he was afebrile and hemodynamically stable, but was diffusely jaundiced with moderate epigastric tenderness. Total bilirubin/direct bilirubin was 29.3/15 mg/dL, AST/ALT 341/311 U/L, alkaline phosphotase/GGT 1928/944 IU/L, CA-19-9 >1500. Ultrasound revealed a 20-mm common bile duct (CBD) and gallbladder sludge. A computed tomography (CT) revealed severe dilation of intra- and extrahepatic bile ducts with tapering into the head of pancreas (HOP), and mild prominence of the HOP without obvious mass lesions. Differential diagnosis of malignancy and autoimmune pancreatitis/cholangiopathy were considered. Endoscopic ultrasound (EUS) revealed dilated CBD (19 mm) and dilated cystic duct (CD) 10 mm with low insertion. A single, round, hyperechoic defect (15 mm) with acoustic shadowing was noted in the distal CD causing extrinsic compression of the CBD at the level of HOP without any evidence of HOP mass lesion. Endoscopic retrograde cholangiopancreatography (ERCP) revealed non-dilated pancreatic duct and 15-mm oval filling defect in the CD causing distal CBD compression. After a biliary sphincterotomy and selective cannulation of CD, a large stone was removed using a basket. Post-procedure there was a significant improvement in liver function tests and CA 19-9 down-trended and eventually normalized in 6 weeks. Discussion: Obstructive jaundice, weight loss, and high levels of CA 19-9 along with radiologic findings of CBD narrowing are highly suggestive of pancreatobiliary malignancy. However, benign disorders such as cholelithiasis, choledocholithiasis, and autoimmune process should be considered in the differential diagnosis. This case represents typical presentation of Mirizzi's syndrome type 1B. EUS is a valuable tool for accurate diagnosis of distal biliary pathology. ERCP with stone extraction from the cystic duct is safe and effective. Elevated levels of CA 19-9 usually point to a neoplastic phenomenon; however, one must thoroughly rule out benign causes.Figure: ERCP image: cystic duct filling defect.