[Hepatic echinococcosis that required 11 years for a definitive diagnosis: a case report].

A woman in her 80s underwent computed tomography that revealed a 22-mm-sized unilocular mass in segment 4 of her liver. The mass grew to 26mm at the 4-year follow-up and to 36mm at the 11-year follow-up, becoming a multilocular mass that invaded the bile duct. At this point, the patient was diagnosed with hepatic echinococcosis based on a serological examination and oral albendazole treatment was initiated. The patient developed cholangitis and underwent endoscopic biliary stenting 12 years after her initial diagnosis. We consider this case valuable as it allowed us to follow the natural course of hepatic echinococcosis.