An unusual presentation of amebic liver abscesses

Our presumptive diagnosis was multiple pyogenic abscesses, which are most often caused by a polymicrobial flora of Streptococcus anginosus, Staphylococcus aureus, Streptococcus pyogenes, Klebsiella pneumoniae and others. We gave our patient parenteral piperacillin-tazobactam therapy. A diagnostic ultrasound-guided drainage of one abscess yielded a viscous, reddish-yellowish fluid. Cultures and Gram staining of the aspirate yielded negative results, as did blood cultures. The histology of the liver biopsy showed nonspecific inflammatory infiltrates. Stool samples were negative for bacteria and protozoa. Results of serologic testing for amebiasis were negative with an indirect immunofluorescence assay and inconclusive with an enzyme-linked immunosorbent assay. The "gold standard" treatment is with a nitroimidazole, such as metronidazole, over 7 to 10 days, followed by a luminal amebicide (paromomycin, iodoquinol or diloxanide furoate).8 In most patients with amebic abscesses, nitroimidazole treatment is highly effective and drainage is usually not necessary. 2 According to published case series and expert opinions, percutaneous drainage or needle aspiration is recommended for exclusion of pyogenic abscesses or if there is no adequate response to nitro imidazole therapy after 3-5 days. Drainage is also recommended for large abscesses in the left lobe of the liver (because of the risk of rupture into the pericardium) and for abscesses with imminent risk of rupture (> 300 cm3).1,2,6 Polymerase chain reaction testing of the aspirate can help establish the diagnosis.9 Our report illustrates that the diagnosis of amebic liver abscess can be challenging. E. histolytica can cause multiple liver abscesses without diarrhea, without a recent stay in a disease-endemic region and without an initial positive serologic test result. Sexual transmission can occur via anal-oral sexual contact, particularly between bisexual and homosexual partners. Therefore, a sexual history should be included in the workup of hepatic abscesses, especially in the absence of travel to a country where amebiasis is endemic.