Peribiliary gland histology. Hematoxylin and eosin stain (H&E stain) demonstrating the presence of PBGs within the wall of the common bile duct of normal adult liver. PBGs (arrows) are tubular-alveolar structures composed of serous and mucinous acini located in the extrahepatic and large intrahepatic bile ducts. PBGs are located in the deeper tissue of the bile duct walls near fibromuscular layers (arrow heads) with some lobules found outside the bile duct walls. The PBGs communicate with the lumen through ducts that open into the diverticula. Magnification (M) .