Refractory primary hepatic actinomycosis with direct infiltration to the diaphragm and thorax: the usefulness of contrast-enhanced ultrasonography.

An 80-year-old man was admitted to our hospital with a diagnosis of primary hepatic actinomycosis determined based on a percutaneous aspiration biopsy. The abscesses and state of liquefaction were easily and effectively visualized on contrast-enhanced ultrasonography. Ampicillin/sulbactam was administered; however, lesions of hepatic actinomycosis suddenly infiltrated the diaphragm and right thorax six months later. A drainage tube was inserted into the right thoracic space, and the pleural effusion gradually decreased. The patient received continuous antibiotic therapy for nearly two years and remained free of hepatic actinomycosis on follow-up more than one year later.