Intra- and extra-abdominal actinomycosis mimicking urachal tumor in an intrauterine device carrier: a case report.

Actinomycosis is a rare, chronic suppurative infection caused by the Gram-positive anaerobic filamentous bacterium, Actinomyces israeli. In most cases, the diagnosis is made postoperatively because of its unusual clinical presentation. Abdominal actinomycosis is the second most common site of the disease and may mimic abdominal cancer, inflammatory bowel disease or diverticulitis. The abdominal-pelvic form of this disease mostly results from the prolonged use of an intrauterine device. We report a rare case of combined intra- and extra-abdominal actinomycosis mimicking urachal tumor that was diagnosed by computed tomography, which presented as two tender abdominal palpable masses following long-term intrauterine device use. The disease was confirmed by postoperative histopathologic examination, which revealed sulfur granules microscopically, and was successfully treated by complete surgical resection following a period of appropriate antibiotic treatment.