Injured bile ducts surrounded by a dense infiltrate of mononuclear cells, most of which are lymphocytes, these florid, asymmetric destructive lesions of interlobular bile ducts
are irregularly scattered throughout the portal triads and often seen only on large surgical biopsies of the liver in which adequate representation of small bile ducts occurs; inflammation is confined to the portal trials (Hirschfield, 2011).
Diseases of the proximal pathways of the biliary system include (1) those that affect the interlobular bile ducts and (2) those that affect the bile canaliculi.
The smallest bile ducts, the interlobular bile ducts, which measure less than 100 im in diameter, are not visualized radiographically.
The canals of Hering drain into bile ductules, which are larger channels with a circumferential lining of cholangiocytes, which in turn drain into interlobular bile ducts.
Primary biliary cirrhosis typically affects interlobular bile ducts that are less than 100 [micro]m in diameter.
The common form of PSC affects the larger bile ducts, both extrahepatic and intrahepatic, whereas about 5% of cases comprise the small-duct variant, which affects the interlobular bile ducts.
Extensive bile duct damage with relatively mild portal inflammation is the most characteristic feature of GVHD, mostly affecting the interlobular bile ducts (Figure 6).
They also documented progressive arterial thickening when the Kasai specimen was compared to the explanted liver in several cases, which was associated with disappearance of interlobular bile ducts.
Interlobular bile duct injury or inflammation has been reported in 31% to 94% of cases (77,87,88) and bile duct loss, in approximately 8% of cases, on initial biopsy samples.