Amebic Liver Abscess Complicated With a Pleural Effusion: A Case Report

Amebiasis is a fecal-oral transmitted parasitic infection caused by the protozoan Entamoeba histolytica, and is generally seen in migrants and travelers of endemic areas. Extraintestinal infection often involves the liver, causing amebic liver abscesses. Twenty to thirty percent of these patients have pleuropulmonary involvement as a complication. The diagnosis is based on clinical, imaging, and serology studies. A 35-year-old male from New Guinea presented to the emergency department with right upper quadrant pain that radiates to the right shoulder, epigastric pain, and fever. Laboratory results showed an increase in hepatic enzymes; days later leukocytosis was reported. Ultrasound revealed hepatomegaly with heterogeneous masses, and three complex cystic hepatic abscesses were found on a CT scan. Percutaneous drainage was placed. Chest X-ray showed bilateral pleural effusion that required a thoracentesis days after. A pigtail catheter was placed. Three amebic antibody tests were performed with a negative result for the first time, equivocal on the second time, and a positive result on the last one. Twenty-six days later the patient was discharged. Amebiasis is a rare and benign condition in the United States, that can cause abdominal cramping, watery diarrhea, and weight loss. A very low percentage of patients will develop an amebic liver abscess, which can be fatal. Amebic liver abscess may rupture and spread to the peritoneum, pleural space, or pericardium. The serum antigen followed by the serology test contributes to the accurate diagnosis. The first antibody amebic test performed on a patient, has a high probability of a false negative result, due to this possibility, the test must be repeated. Metronidazole remains the drug of choice, and therapeutic aspiration is occasionally required as an adjunct to antiparasitic therapy.