Introduction:Polycystic liver disease is a benign condition that may be complicated by cyst superinfection or vascular and biliary compression. The occurrence of Budd–Chiari syndrome (BCS) secondary to an amebic superinfection of a hepatic cyst is exceptionally rare and requires multidisciplinary management.

Case Report:We report the case of a 65-year-old man, followed since 2012 for polycystic liver disease, with two large cysts measuring 6 cm (segment IV) and 14 cm (segment III). He presented with cyst superinfection revealed by a clinical and biological cholestasis syndrome in a febrile context, following a recent episode of foodborne illness. Hepatic Doppler ultrasound, angio-CT, and liver MRI demonstrated BCS caused by compression of the hepatic veins by two large infected cystic formations.The patient received intravenous antibiotics and underwent radiological drainage, yielding a “chocolate-colored” fluid highly suggestive of amebic infection, later confirmed by strongly positive ELISA serology. Follow-up imaging one month after drainage showed a 70% reduction of the segment VIII cyst but persistence of the left-lobe cyst, prompting a second drainage.A subsequent evaluation one month later showed significant collapse of both cysts and complete relief of the compression on the right hepatic vein and IVC, indicating successful management.

Conclusion:This case highlights a rare and complex complication of polycystic liver disease: amebic superinfection leading to Budd–Chiari syndrome. It underscores the importance of regular clinical and radiological monitoring to detect early warning signs and ensure timely, multidisciplinary intervention to optimize patient outcomes.