RESUMO
Background Liver abscess is the most common extraintestinal manifestation of Entamoeba histolytica. Clinical manifestations could appear after returning from an endemic area or several years after the exposure. The diagnosis usually requires microbiological confirmation. Case presentation We present a case of a 55-year-old woman diagnosed with Crohn's disease treated with immunosuppressive drugs, who was admitted to the Emergency Service with liver parenchyma abscesses. Computed tomography (CT)-guided puncture showed pus, and both Gram staining and fresh parasite visualization were negative. Hepatic pus bacteriological culture was reported as negative and parasite multiplex polymerase chain reaction (PCR) was performed, being positive for E. histolytica. The same PCR was performed on blood, pleural fluid and stool samples, all of them being positive for E. histolytica. Conclusions Reviewing the clinical history of this patient, it was observed that parasite detection in three stool samples was negative 2 months before the current admission. Due to the lack of sensitivity of the microscopy techniques, we propose to routinely perform parasite detection in stools using molecular techniques, especially in immunocompromised patients.