Primary Hepatic Actinomycosis

The clinical and imaging findings of primary hepatic actinomycosis are nonspecific and can mimic other diseases. This condition usually needs to be distinguished from other liver-occupying lesions, including malignancy. Review of the English language literature showed 67 cases of hepatic actinomycosis in immunocompetent, predominantly male patients. Infection was usually (75%) cryptogenic. The results of radiologic imaging showed that the lesion involved the right lobe in half of the cases, mimicked a liver tumor in 45%, and was single in two thirds of the cases. Hepatic actinomycosis coexisted with infections by common bacteria in 32% of cases reported. Diagnosis was usually achieved by microscopic examination of surgical or percutaneous specimens in 84.2% and 78.6%, respectively. Antibiotic therapy alone was used for treatment in approximately one half of cases and combined antibiotic treatment with surgical or percutaneous drainage procedure in the other half. The overall mortality rate was 7.6%. In conclusion, primary hepatic actinomycosis is a rare and usually cryptogenic infection. It is more common in men and immunocompetent subjects. It is well responsive to medical or combined medical and interventional treatment.