Pelvic actinomycosis: Is long-term antibiotic therapy necessary?

OBJECTIVE: To describe 11 cases of actinomycosis and analyze whether long-term antibiotic use is necessary. STUDY DESIGN: Analysis of 11 cases of pelvic actinomycosis diagnosed and treated during the last nine years. Four patients had an intrauterine device (IUD) for 6-20 years, three patients had an IUD for 3-5 years, and four patients had no known etiology. In most patients the symptoms lasted from several days to one month. The actinomycotic lesions involved one or both ovaries in all 11 cases. In five patients the lesion extended to other areas, such as the uterus, omentum, parametrium, pelvic walls, colon, bladder, cul-de-sac and gallbladder. RESULTS: All patients underwent surgery that included removal of the lesions with the ipsilateral or both adnexa and, in specific cases, with extension of the lesions, hysterectomy, omentectomy, hemicolectomy and cholecystectomy. Confirmation of the diagnosis of actinomycosis was done by histology in all cases, and antibiotic treatment usually began 1-14 days after surgery. The drug of choice was penicillin. The duration of treatment was 12 months in 6 patients, 6 months in 3 and ≤3 months in two. All patients were alive and well after two to nine years of follow-up. CONCLUSION: In contrast to actinomycosis at other sites, where the literature recommends antibiotic therapy for 6-12 months, pelvic actinomycosis could be a limited disease. We propose that in cases of pelvic actinomycosis where the abscess can be completely removed surgically, a shorter period of antibiotic therapy can be effective.