[A case of hepatic actinomycosis diagnosed by thin needle aspiration biopsy successfully treated with antibiotics].

A 57-year-old man presented with chief complaints of right hypochondrial pain and fever. Laboratory tests revealed severe inflammatory reactions. Abdominal ultrasonography disclosed a mass with non-homogeneous internal echoes suggesting hepatic abscess. Percutaneous liver biopsy revealed a lump of actinomycetes, allowing a diagnosis of hepatic actinomycosis. The abscess disappeared following long-term treatment with penicillin antibiotics. Actinomycosis developing primarily in the liver is very rare. This condition needs to be distinguished from tumorous lesions of the liver, including malignancy. It seems noteworthy that the diagnosis of this condition was possible on the basis of percutaneous liver biopsy.