Figure 1: Histological staging in a representative case of a patient with primary biliary. Stage 1 reveals duct-centred inflammation showing chronic nonsuppurative destructive cholangitis (black arrows). A tiny granuloma is also seen (grey arrow). Stage 2 shows portal enlargement (arrows) with bile ductular reaction and inflammatory cell infiltration. Stage 3 is characterized by fibrous scaring bridging portal tracts with occasional foci of bile duct loss (no bile duct identified around an artery indicated by arrow). Stage 4 shows cirrhotic transformation.