case_images: PMC11337904_01
case_images: (a) Transabdominal ultrasound: A 38 x 30 mm cystic lesion with a hyperechoic lobulated solid component was observed in S1/4. There were no findings suggestive of necrosis or hemorrhage, and the margin was clear. (b) Computed tomography: A cystic lesion measuring 38 x 34 mm with papillary growth in S1/4 just above the perihilar bile duct. (c) Magnetic resonance cholangiopancreatography: The lesion was widely bordered by the left and right hepatic ducts, but the connection with the cyst was unclear. (d) Endoscopic ultrasonography: Contrast-enhanced endoscopic ultrasonography via Sonazoid revealed deep staining in the lobulated solid component, beginning in the early phase with a prolonged contrast effect.
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case_images: Transabdominal ultrasound (Figure 1a) revealed a 38 x 30 mm cystic lesion with a hyperechoic lobulated component in S1/4. Contrast-enhanced computed tomography (Figure 1b) showed a cystic lesion measuring 38 x 34 mm with papillary growth in S1/4 just above the perihilar bile duct. Magnetic resonance imaging (Figure 1c) showed that the lesion was widely bordered by the left and right hepatic ducts on magnetic resonance cholangiopancreatography but the connection was unclear. Endoscopic ultrasonography (Figure 1d) revealed a cystic lesion in S1/4.
case_images: (a) A linear translucent image was observed in the common bile duct, which suggested mucus accumulation. (b) A cystic lesion with an internal irregular defect above the perihilar bile duct (yellow arrow), but accurate localization of the connection was difficult to identify via only endoscopic retrograde cholangiography. (c) The left hepatic duct was in contact with the lesion, but the layered structure of the cyst was preserved (blue arrow). (d) The right hepatic duct lost bile duct continuity, and the tumor was exposed to the bile duct lumen (red arrow).
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case_images: Endoscopic retrograde cholangiopancreatography (Figure 2a,b) showed a linear translucent image in the common bile duct, which suggested mucus accumulation. Intraductal ultrasonography (Figure 2c,d) showed that the left hepatic duct was in contact with the lesion, but the layered structure of the cyst was preserved.
case_images: (a) The connection with the cystic lesion was located in the right hepatic duct, and villous mucosa was protruding through the conduit lumen. No superficial extension to the bile duct was observed. (b) A large amount of mucobilia drained from the cyst. (c) The tumor biopsy was performed precisely, and attributed to direct visualization. (d) Papillary epithelial neoplasm, suspicious for adenocarcinoma, was observed only in the lesion.
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case_images: POCS (Figure 3a-c), using SpyGlass DS (Boston Scientific), revealed that the connection was located in the right hepatic duct, and the villous mucosa protruded through the conduit lumen. Biopsy pathology (Figure 3d) revealed a papillary neoplasm, suspicious for adenocarcinoma, only in the lesion, while biopsies of other sites showed no neoplastic changes.
case_images: (a) The tumor (red circle) protruded into the right hepatic duct (green line). (b) The intraductal papillary neoplasm of the bile duct (IPNB) was connected to the right hepatic duct, and the papillary tumor within the cyst had spread through the conduit lumen (blue arrow). (c) Papillary growth of the neoplastic epithelium was observed on the surface of the fibrovascular stalks (green arrow). Non-neoplastic peribiliary glands were observed near the IPNB (white arrow). (d) The tumor epithelium was papillary growth and accompanied by large and clear cells containing mucus, suggesting gastric-type IPNB. Low-grade and high-grade dysplasia were also observed within the IPNB.
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case_images: The postoperative pathology (Figure 4) confirmed that the lesion was connected to the right hepatic duct.