Fig. 1. Formation of a liver abscess after insertion of a unilateral metal stent in a patient with hilar cholangiocarcinoma. (A) Inoperable papillary-type cholangiocarcinoma (white arrow) diagnosed as Bismuth type IV based on the initial computed tomography scan. (B) A self-expandable metal stent was inserted unilaterally in the left lobe via the percutaneous tract after failed endoscopic stenting. (C) The stent was occluded due to tumor in-growth after 8 months. (D) The liver abscess developed in the right lobe, the contralateral side during stent insertion.