Primary hepatic actinomycosis mimicking a malignant liver tumor: Case report and review of the Latin American literature

Abstract

Hepatic actinomycosis is a rare infection caused by Actinomyces spp. It is characterized by nonspecific clinical presentation and imaging findings that may mimic hepatic neoplasms. We report the case of a 43-year-old man presenting with a three-month history of right upper quadrant pain and weight loss. Magnetic resonance imaging revealed an infiltrative hepatic mass involving segments IV, V, and VIII, suggestive of malignancy. Percutaneous biopsy was inconclusive; therefore, an extended right hepatectomy with segmental colectomy was performed. The definitive diagnosis was established by histopathological examination, which demonstrated sulfur granules and filamentous structures consistent with Actinomyces spp. The patient received prolonged antibiotic therapy, with favorable clinical evolution and no evidence of recurrence during follow-up. Hepatic actinomycosis is an entity with limited representation in the Latin American literature and should be considered in the differential diagnosis of atypical liver masses, even in the absence of predisposing factors. Its presentation may mimic hepatic malignancy and lead to unnecessary major surgical interventions. In clinical practice, it is essential to maintain a high index of suspicion for infectious etiologies, particularly when initial biopsies are inconclusive.