Actinomycotic Endocarditis of the Eustachian Valve: A Rare Case and a Review of the Literature

Eustachian valve endocarditis caused by Actinomyces species is extremely rare. A literature review revealed only one reported case—caused by Actinomyces israelii in an intravenous drug abuser.Our patient, a 30-year-old woman who at first appeared to be in good health, presented with fever, a large mobile mass on the eustachian valve, and extensive intra-abdominal and pelvic masses that looked malignant. Histopathologic examination of tissue found in association with an intrauterine contraceptive device revealed filamentous, branching microorganisms consistent with Actinomyces turicensis. This patient was treated successfully with antibiotic agents.In addition to presenting a new case of a rare condition, we discuss cardiac actinomycotic infections in general and eustachian valve endocarditis in particular: its predisposing factors, clinical course, sequelae, and our approaches to its management.