Abstract
INTRODUCTION: Amebic liver abscess is a parasitic infection caused by Entamoeba histolytica, which reaches the liver via the portal circulation after invading the colon. While it typically presents with fever, right upper quadrant pain, and elevated inflammatory markers, its clinical and radiologic features can resemble those of bacterial liver abscesses. In patients with structural liver abnormalities, such as polycystic liver disease, symptoms may be atypical and delay diagnosis. CASE PRESENTATION: We report the case of a 75-year-old woman with autosomal dominant polycystic kidney disease and multiple liver cysts, who presented with abdominal distension and gastrointestinal symptoms. MRI revealed multiple liver cysts, including a large lesion with heterogeneous signal intensity, initially suspected to represent intracystic hemorrhage. The patient underwent open cyst fenestration and deroofing. Postoperatively, she developed persistent ascitic fluid drainage and acute kidney injury requiring dialysis. Despite elevated inflammatory markers, she remained afebrile, and bacterial cultures from blood and ascitic fluid were negative. Histopathological analysis of the resected cyst wall revealed numerous trophozoites consistent with E. histolytica, and subsequent stool and ascitic fluid antigen tests confirmed the diagnosis. The patient was treated with a 16-day course of metronidazole followed by 7 days of paromomycin, resulting in clinical improvement and eventual discharge. CONCLUSIONS: For high-risk patients with complex hepatic cysts of uncertain cause, begin with percutaneous aspiration and targeted fluid analyses-including testing for E. histolytica-before invasive surgery; this lowers operative risk and aids detection of amebic liver abscess in atypical or culture-negative presentations.