PC2186: Tubo-ovarian Abscess in a Non-sexually Active Adolescent Female: an Uncommon Diagnosis

Introduction: Tubo-ovarian abscess (TOA) is a known complication of pelvic inflammatory disease in sexually active females of reproductive age. While pelvic inflammatory disease is commonly caused by Neisseria gonorrhea and Chlamydia trachomatis, TOAs are typically polymicrobial. TOAs are treated with broad spectrum antibiotics and many require drainage. In contrast to the sexually active population, TOA is a rare occurrence in non-sexually active female adolescents. We report a case of a TOA in a previously healthy, non-sexually active 14 year old female caused by Streptococcus anginosus.

Case Description: The patient is an athletic, adolescent, female without a history of sexual activity or high-risk behaviors. She presented with 6 days of fever, lower abdominal pain, and diarrhea. Magnetic resonance imaging (MRI) demonstrated a 5.2 x 4.5 x 5.2 centimeter abscess within the left adnexa causing marked enlargement of the left fallopian tube and ovary (Figure 1a). Neisseria gonorrhea and Chlamydia trachomatis testing was negative. After 3 days of treatment with ceftriaxone, doxycycline, and metronidazole, fever persisted and she subsequently underwent laparoscopic irrigation and debridement (Figure 2). Cultures were negative. Her fevers recrudesced 3 days later, and repeat MRI found re-accumulation of the abscess (Figure 1b). Interventional radiology (IR) percutaneously drained the abscess, after which she defervesced. The IR culture grew Streptococcus anginosus. While hospitalized, she was treated with 12 days of the antibiotic course above, and then at discharge transitioned to oral levofloxacin and metronidazole for an additional 24 days to complete a total of 36 days of antibiotics. Repeat MRI showed near-complete resolution of the pelvic inflammatory process and no identifiable abscess (Figure 1c).

Discussion: TOAs in non-sexually active females are rare, with approximately 53 cases in the literature. The mechanism of infection is not well understood, but reported risk factors include obesity, recurrent urinary tract infection, poor hygiene, and abnormal genitourinary anatomy. Interestingly, our patient had none of these risk factors. Treatment requires broad spectrum antibiotics for polymicrobial infection, and over half of patients require drainage for source control. Size of the abscess is most predictive for the need for surgical intervention; and conversely, inflammatory markers such as CRP or ESR, while typically elevated, are not predictive of need for drainage. Most cases do not isolate bacteria, but when identified, causative organisms include S. pneumonia, E. coli, viridans group Streptococci, the Streptococcus anginosus group, and anaerobes including Prevotella species and Bacteroides fragilis. Antibiotic duration varies, but is usually for at least 10 to 14 days, although longer courses may depend on source control, clinical response, and follow-up imaging.

Conclusion: This case highlights that early recognition is key to diagnosis and appropriate management of TOA in a non-sexually active adolescent female. A multi-disciplinary approach is critical to optimize therapeutic options including antibiotics, surgery, and IR drainage.