Black Pigment Gallstones : Pathophysiology

Black Pigment Gallstones - Pathophysiology (continued from the previous image): Black gallstones are not associated with biliary infections and usually form in gallbladder of older individuals. They occur in the following settings:

• increased formation of bilirubin conjugates (e.g. chronic hemolysis in β-thalassemia, sickle cell disease, hereditary spherocytosis)
• ineffective erythropoiesis (e.g. pernicious anemia)
• decreased secretion of bile acids (e.g. cirrhosis)
• ileal pathology (e.g. Crohn's disease, extended ileal resections)
• increased phospholipid synthesis (e.g. carbohydrate-rich diets, total parenteral nutrition)

These alterations lead to an excess of unconjugated bilirubin in bile which precipitates as calcium bilirubinate to form pigment stones.