A Forgotten Encounter: A Case of Amebic Liver Abscess Mimicking Hepatic Malignancy in a Non-endemic Region

Amebic liver abscess (ALA), caused by Entamoeba histolytica, is prevalent in endemic regions such as Central/South America, Southeast Asia/India, and Africa but is considered rare in North America. Symptoms of E. histolytica infection typically emerge eight to 20 weeks after exposure in endemic areas. We present the case of a 58-year-old woman who developed right-sided abdominal pain, weakness, fever, and significant weight loss. Radiological imaging revealed a large, non-cystic hepatic mass, raising suspicion of malignancy. Notably, the patient had not traveled to an endemic region in the past year. An ultrasound-guided liver biopsy drained 500 mL of purulent, grayish fluid. Cultures for bacteria and cytology for malignancy were negative. Further serological testing confirmed the diagnosis of ALA with positive E. histolytica IgG antibodies. The patient was treated with oral metronidazole, resulting in rapid symptomatic improvement. This case underscores the diagnostic challenges associated with ALA in non-endemic regions, particularly when initial presentation, imaging findings, and absence of recent travel history suggest hepatic malignancy. It highlights the importance of considering ALA in the differential diagnosis of hepatic masses, even in patients without clear exposure to endemic regions.