Ascaris in bile duct mimicking a plastic biliary stent on endoscopic ultrasound

Abstract

An 18-year-old female presented with recurrent pain abdomen of 1-month duration. Laboratory investigation suggested raised serum amylase and lipase with mildly abnormal liver functions. Ultrasonography abdomen showed mildly dilated common bile duct (CBD) with normal gall bladder and pancreas. Endoscopic ultrasound, with a radial echoendoscope, showed mildly dilated CBD having a long linear echogenic structure having tram track appearance extending along its entire extent (similar to a plastic biliary stent). The pancreas appeared normal. At endoscopic retrograde cholangiopancreatography, the papilla was normal and cholangiogram on selective biliary cannulation confirmed the presence of long linear filling defect in entire length. Biliary sphincterotomy and balloon sweep showed an intact dead Ascaris worm. Since then, the patient has no recurrence of pain.