In most cases, it is not difficult to differentiate common bile duct (CBD) stone from Ascaris infection because they are different disease entities and have different imaging findings. The two diseases usually demonstrate unique characteristic findings on computed tomography or magnetic resonance cholangiopancreatography. However, we report a rare case from our experience in which a CBD stone mimicked and was misdiagnosed as Ascaris.
A 72-year-old male presented with elevated serum liver enzymes. Computed tomography showed a hyper-attenuated, elongated lesion in the CBD lumen and associated biliary inflammation. Magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography revealed a linear filling defect in the bile duct. Moreover, elongated echogenic material with a central hypoechogenic area was seen on endoscopic ultrasound. Although the imaging findings caused us to suspect infection with the nematode Ascaris, the lesion was revealed to be a dark-brown-colored CBD stone through endoscopic extraction.
We report a rare case of a CBD stone that mimicked Ascaris. We also review the literature for side-by-side comparisons of the imaging features of CBD stones and ascariasis.
World journal of clinical cases. 2020 Oct 06 [Epub]
Seo-Youn Choi, Ha Eun Jo, Yun Nah Lee, Ji Eun Lee, Min Hee Lee, Sanghyeok Lim, Boem Ha Yi
Radiology, Soonchunhyang University Hospital, Bucheon, Bucheon 14584, South Korea. ., Radiology, Soonchunhyang University Hospital, Bucheon, Bucheon 14584, South Korea., Digestive disease center and research institute, Soonchunhyang University Hospital, Bucheon, Bucheon 14584, South Korea.
This webpage is supported through an unrestricted educational grant from Bayer. Bayer is not involved in content development and the views expressed represent those of the patient and physician contributors.

