Hepatic actinomycosis mimicking an isolated tumor recurrence

Actinomyces species has been described as an opportunistic pathogen, particularly in the oral cavity; however, in rare cases these bacteria can cause actinomycosis which is characterized by formation of abscesses in the mouth, lungs, or gastrointestinal tract. Actinomycosis was commonly present in the pre-antibiotic era; however, it has a low prevalence now days. It has been recognized since 150 years ago, but because of its variable clinical presentation and indolent course, its recognition is difficult and patients are often misdiagnosed. Here we present a case of primary hepatic actinomycosis presenting as a metastatic liver tumor.