Pelvic actinomycosis presenting with a large abscess and bowel stenosis with marked response to conservative treatment: a case report.

Pelvic actinomycosis is a rare disease that can result in abscess formation, bowel obstruction, and other serious complications. Moreover, the correct diagnosis can seldom be established before radical surgery because the disease often mimics pelvic neoplasms. It has been recently recognized that pelvic actinomycosis is associated with long-term use of an intrauterine contraceptive device.We report a woman with a long-standing intrauterine contraceptive device who visited our hospital complaining of symptoms mimicking large bowel ileus with a subacute course. X-ray fluorography and sigmoidoscopy showed marked stenosis in the sigmoid colon but rejected the possibility of colon cancers. Abdomino-pelvic CT and MRI revealed a huge abscess lying over the urinary bladder and anterior to the uterus. Furthermore, a cervical Papanicolaou smear disclosed Actinomyces species. We removed the intrauterine device from the patient. Subsequent high-dose ampicillin administration led to dramatic shrinkage of the abscess and improved the management of the bowel movement quickly. This is a successful case of symptomatic pelvic actinomycosis that was correctly diagnosed and treated without unnecessary surgical intervention.