Hepatosplenic actinomycosis in an immunocompetent patient.

Hepatosplenic abscess caused by Actinomyces is rare and often misdiagnosed as malignancy. Herein, we report a case of hepatosplenic actinomycosis in a 37-year-old immunocompetent man with a 2-month clinical history of intermittent fever and upper left abdominal pain. Physical examination revealed a mildly ill-appearing man with a low-grade fever (38°C) and upper left quadrant abdominal tenderness. Abdominal sonographic examination showed the presence of a 6.3 cm × 6.5 cm heterogeneous abscess with a hypoechoic center and honeycomb appearance in an enlarged spleen (8 cm × 5 cm). Computerized tomography of the abdomen revealed a multiloculated splenic lesion, and laparotomy showed multiple hepatic nodules and a splenic abscess. Histopathological examination of the biopsy revealed filamentous branching bacilli and sulfur granules in the hepatosplenic abscess. The patient successfully underwent splenectomy accompanied by intravenous and oral penicillin treatment. Proper and prompt diagnosis of hepatosplenic actinomycosis is important because the therapeutic plan and prognosis of this pathogen are quite different from other microorganisms and malignancies.