Retroperitoneal fibrosis with ureteral obstruction secondary to Actinomyces israeli.

A case of Actinomycosis israeli causing retroperitoneal fibrosis and ureteral obstruction is presented. This rare occurrence followed direct extension of the infectious process from intra-abdominal abscesses to the retroperitoneum, resulting in dense fibrosis. Diagnosis is most commonly established by histologic identification of sulfur granules obtained at abdominal exploration. The pathogenesis and treatment of genitourinary as well as retroperitoneal actinomycosis is discussed.