Biliary ascariasis and extrahepatic cholangiocarcinoma: a report of two cases.

We report two cases of rural Malay women in Perak, Malaysia, with extrahepatic cholangiocarcinoma and coexistent biliary ascariasis. In both cases, the narrowed bile duct may have resulted in inability of the migratory nematode to return to the gastrointestinal tract. It may be reasonable, also, to postulate that chronic biliary tract infestation by Ascaris lumbricoides may have contributed to the development of cholangiocarcinoma; a situation similar to that observed in liver fluke infestation.