Pelvic Actinomycosis Related to Intrauterine Device: A Case Report.

Actinomycosis is a rare but persistent bacterial infection caused by  spp., a Gram-positive bacillus that typically inhabits the oropharynx and gastrointestinal and urogenital tracts. It can infiltrate deeper tissues following trauma, surgery, or foreign body presence, forming granulomatous masses of filamentous bacilli. While cervicofacial actinomycosis is the most prevalent form, pelvic actinomycosis has been strongly associated with prolonged intrauterine device (IUD) use, where chronic irritation of the endothelium facilitates bacterial invasion. Diagnosing actinomycosis can be challenging due to its slow progression and clinical resemblance to malignancies. This report presents a case of a 71-year-old woman with postmenopausal uterine bleeding, abdominal mass, anemia, and weight loss. Imaging identified a complex pelvic mass, and surgical biopsy confirmed pelvic actinomycosis. The patient was treated with high-dose intravenous penicillin followed by prolonged oral antibiotic therapy. Additionally, a degraded, retained IUD suspected as the infection source was removed. A follow-up MRI showed a significant reduction in abscess size after one year of treatment. An actinomycosis diagnosis is crucial for effective treatment planning, with beta-lactam antibiotics being the cornerstone of therapy. However, severe cases may necessitate surgical drainage or resection. Given its ability to mimic other gynecological conditions, early recognition and appropriate management of pelvic actinomycosis, including prompt IUD removal when indicated, are essential for optimal patient outcomes.