Pelvic actinomycosis infection is rare but serious infection caused by Actinomyces sp, an opportunistic gram-positive bacteria usually introduced by foreign bodies specially IUCDs, surgery, or trauma. It generally falls under the broader spectrum of pelvic inflammatory disease.
Pelvic infection from several actinomyces sp can occur, which include:
- Actinomyces israelii: by far the commonest causative organism 3
- Actinomyces naeslundii
- Actinomyces viscosus
- Actinomyces eriksonii
The organisms are indigenous in the oral cavity, gastrointestinal tract, and genital tract, with opportunistic infection occurring when the mucosal barrier is broken.
- placement of intra-uterine contraceptive devices: usually when it has been present for a prolonged period
- approximately 25% of IUCDs eventually get colonised by actinomycosis
- 2-4% of IUCDs that are colonised ultimately develop a serious actinomycotic infection
Actinomycosis infection can mimic many other pelvic pathologies on imaging. The spread of infective/inflammatory change across tissue planes in particular retroperitoneal extension into the psoas muscle may suggest towards the diagnosis. Most common site of involvement in GI system is iliocaecal junction.
- indurated pelvic fat
- pelvic free fluid
- pelvic abscess
- wider Intra-abdominal extension: mainly through contiguous spread
- formation of tubo-ovarian abscesses 2
- subsequent infertility
Treatment and prognosis
Treatment is usually with IV Penicillin in uncomplicated cases. The presence of an associated complication such as a tubo-ovarian abscess would warrant surgical intervention.
Due to its non specific imaging appearances, pelvic actinomyces infection can mimic several pathology such as:
- 1. O'connor KF, Bagg MN, Croley MR et-al. Pelvic actinomycosis associated with intrauterine devices. Radiology. 1989;170 (2): 559-60. Radiology (abstract) - Pubmed citation
- 2. Kim SH, Kim SH, Yang DM et-al. Unusual causes of tubo-ovarian abscess: CT and MR imaging findings. Radiographics. 24 (6): 1575-89. doi:10.1148/rg.246045016 - Pubmed citation
- 3. Lely RJ, Van es HW. Case 85: pelvic actinomycosis in association with an intrauterine device. Radiology. 2005;236 (2): 492-4. doi:10.1148/radiol.2362031034 - Pubmed citation
- 4. Williams CE, Lamb GH, Lewis-jones HG. Pelvic actinomycosis: beware the intrauterine contraceptive device. Br J Radiol. 1990;63 (746): 134-7. doi:10.1259/0007-1285-63-746-134 - Pubmed citation
- 5. Lee IJ, Ha HK, Park CM et-al. Abdominopelvic actinomycosis involving the gastrointestinal tract: CT features. Radiology. 2001;220 (1): 76-80. Radiology (full text) - Pubmed citation
- 6. Hawnaur JM, Reynolds K, Mcgettigan C. Magnetic resonance imaging of actinomycosis presenting as pelvic malignancy. Br J Radiol. 1999;72 (862): 1006-11. Br J Radiol (abstract) - Pubmed citation
- 7. Hawnaur JM, Reynolds K, Mcgettigan C. Magnetic resonance imaging of actinomycosis presenting as pelvic malignancy. Br J Radiol. 1999;72 (862): 1006-11. Br J Radiol (abstract) - Pubmed citation
- 8. Goodwin TM, Montoro MN, Muderspach L et-al. Management of Common Problems in Obstetrics and Gynecology. Wiley-Blackwell. (2010) ISBN:1405169168. Read it at Google Books - Find it at Amazon