Retroperitoneal actinomycosis: a case report and review of the literature.

A 25-year-old Haitian man presented with a post-traumatic left retroperitoneal abscess. Culture of material obtained during surgical drainage yielded Actinomyces israelii. Retroperitoneal actinomycosis is a particularly unusual manifestation of infection with this organism. Because it may mimic subacute infections or malignant masses in terms of clinical findings, diagnosis of this entity may be difficult. Our diagnosis was based on the results of culture, and the patient responded to long-term penicillin therapy.