Squamous metaplasia of extrahepatic biliary system in an AIDS patient with cryptosporidia and cholangitis

AIDS-related cholangiopathy is an increasingly recognized syndrome associated with significant morbidity and mortality. The mechanism of cholangiopathy is unknown but is assumed to be related to infectious pathogens such as CMV and cryptosporidia. The case of a Haitian with HIV and long-standing intestinal cryptosporidiosis who presented with cholangitis and protuberant intrabiliary filling defects is reported. Histopathological examination of biliary biopsies revealed previously unreported extensive squamous metaplasia of the bile duct epithelium, and the histogenesis of this condition is discussed. Chronic cryptosporidial infestation may be directly pathogenic resulting in squamous metaplasia that mimics biliary malignancy.