case_images: PMC10827930_01
case_images: Abdominal non-contrast-enhanced computed tomography (NECT) and contrast-enhanced computed tomography (CECT; A: Artery phase, P: Portal vein phase, V: Vein phase) revealed mild dilatation of the bile ducts in the left lobe of the liver. Additionally, low-density areas (indicated by an arrow) were observed along the hepatic longitudinal fissure, extending toward the hepatic hilum. The boundary of these inflammatory areas appeared unclear, accompanied by narrowing and indistinctness of the adjacent left branch of the portal vein. Inflammatory exudation was also present in front of the colon. Moreover, there was thickening of the peritoneum and omentum. During CECT scans, the lesions exhibited gradual and significant enhancement, displaying a consistent and uniform enhancement pattern. However, the density of the lesions at each stage was lower compared to that of the liver parenchyma. Abdominal non-contrast-enhanced MRI (NEMR) and contrast-enhanced MRI (CEMR; A: Artery phase, P: Portal vein phase, V: Vein phase) demonstrated that the inflammatory areas in Segment 3, near the hepatic hilum, appeared as areas with low signals on T1-weighted imaging and high signals on T2-weighted imaging. On diffusion-weighted imaging (b = 800), limited diffusion was observed within the lesions (indicated by a triangle). These lesions measured approximately 3.6 cm x 3.8 cm and displayed a crab-like edge, distinctly separate from the hilar bile duct and blood vessels. Regarding contrast enhancement, the lesions exhibited moderate progressive enhancement on CEMR. Furthermore, lymph nodes in the hilar region were found to have distinct and uniform enhancement on CEMR.
case_images: fmed-10-1340667-g001.jpg
case_images: PMC10827930_01_fmed-10-1340667-g001.jpg
case_images: fig1
case_images: 3D-computed tomography angiography provided a visual depiction of the lesion in the left lobe of the liver, showcasing its extension from the longitudinal fissure toward the patchy shadow in the hilar area. Furthermore, infiltration around the sagittal portion of the bile duct and portal vein was observed. There was notable exacerbation of bile duct dilatation and exudation in front of the colon (indicated by a pentagonal shape), which was more severe compared to previous imaging. Additionally, there was a significant and persistent increase in peripheral absolute eosinophil count.
case_images: fmed-10-1340667-g002.jpg
case_images: PMC10827930_01_fmed-10-1340667-g002.jpg
case_images: fig2
case_images: The inflammatory areas showed enlargement, and intrahepatic bile duct dilation worsened (Figure 2).
case_images: Abdominal NEMR and CEMR revealed a reduction in lesions within the left hepatic lobe and hepatic hilum compared to previous findings. Additionally, there was an improvement in bile duct dilatation, while a new lesion (indicated by arrows) near the right hepatic duct was observed. This imaging feature was referred to as migratory sign.
case_images: fmed-10-1340667-g003.jpg
case_images: PMC10827930_01_fmed-10-1340667-g003.jpg
case_images: fig3
case_images: While the original biliary duct lesions had decreased in size, new lesions with a migratory sign were observed on the upper abdominal MRI (Figure 3).
case_images: Pathological examination (HE staining, 4x and 40x magnification) revealed a uniform and significant thickening of the bile duct walls accompanied by eosinophil infiltration. Additionally, there was a notable presence of eosinophilic infiltration (indicated by a ring) within the adjacent adipose tissue space.
case_images: fmed-10-1340667-g004.jpg
case_images: PMC10827930_01_fmed-10-1340667-g004.jpg
case_images: fig4
case_images: The postoperative pathological examination confirmed the diagnosis of EC (Figure 4).