Pigment stones are associated with excess production of bilirubin for example in:
- chronic haemolysis - for example, hereditary spherocytosis, sickle cell anaemia, thalassaemia, malaria, leukaemia
- hepatic cirrhosis - especially in the Far East where viral hepatitis is common
- bile stasis - for example, a strictured or a markedly dilated common duct
- bacterial infection - 90% of pigment stones comprise dense mixtures of bacteria and bacterial glycocalix along with pigment solids. It is likely that bacterial á-glucoronidase is responsible for deconjugating soluble bilirubin diglucoronide to unconjugated bilirubin, which subsequently becomes agglomerated by glycocalix into macroscopic stones.
Particularly in Asia, pigment stones are associated with infestations:
- Clonorchis sinensis
- Fasciola hepatica
- Ascaris lumbricoides