[An unusual case of hepatic abscess].

Right upper quadrant pain with chronic malaise and fever can be the clinical manifestation of a hepatic infection. An uncommon cause for the disease is hepatic actinomycosis. Actinomycosis was common in the preantibiotic era but is less frequent nowadays; consequently its timely recognition has become more difficult. The clinical and radiological findings often resemble other inflammatory and neoplastic lesions. We report a case of a mixed anaerobic liver abscess including fusobacteria and actinomycetes, without apparent predisposing factor. The diagnosis was obtained by CT-guided percutaneous aspiration of the hepatic mass, where microscopy revealed the presence of fusiform gramnegative bacteria and gram-positive branching filamentous rods consistent with Actinomyces species. The latter did not grow in culture, while the gram negatives were identified as fusobacterium nucleatum. The diagnosis of actinomycosis of the liver is confirmed in only a minority of cases by culture. The disease is usually treated with an extended course of antibiotics. Penicillin is the preferred choice.