Peribiliary Cysts Both in the Cystic Duct and in the Intrahepatic Biliary Tract

Figure 1A 72-year-old man complained of low-grade fever and right upper quadrant abdominal pain. Endoscopic retrograde cholangiopancreatography revealed radiolucent areas in the extrahepatic bile duct (white arrows) and in the cystic duct (large white arrow), suggestive of a gallstone. Cholecystectomy and choledocholithotomy were carried out.

Figure 2 a On the resected specimen, a smooth-surfaced intramural cyst (black arrow) was identified in the cystic duct, in addition to gallstones in the common bile duct and the gallbladder. b, c Photomicrographs show that the cyst is lined with a layer of columnar epithelium, and mildly periductal glands are seen in the cyst wall (hematoxylin and eosin; magnification × 13 (b) and × 135 (c).

Figure 3Magnetic resonance cholangiopancreatography undertaken after surgery demonstrates numerous cysts along the intrahepatic bile ducts in a single image.

Figure 4T-tube cholangioscopy reveals an elevated lesion covered with normal mucosa in the intrahepatic bile duct.