Pigment Gallstones : Introduction

Comments:
Pigment Gallstones - Introduction: They are far more common in Asia and Africa than in Western countries. They make up approximately 20% to 25% of gallstones in the US. Pigment gallstones may be black (shown here) or brown.

Both types have distinct morphology, chemical composition, pathophysiology, and associated clinical conditions. Black pigment gallstones form in sterile gallbladder bile. Brown pigment stones are usually seen in the setting of bacterial or parasitic infections in intrahepatic or extrahepatic bile ducts. Both types are composed mainly of insoluble calcium salts of unconjugated bilirubin in a matrix of mucin glycoproteins and contain < 30% cholesterol.