Ruptured Appendiceal Diverticulum Leading to Tubo-Ovarian Abscess in a Non-Sexually Active Woman: A Case Study

Introduction

Tubo-ovarian abscess (TOA) is a serious complication of pelvic inflammatory disease (PID) that develops in 18–34% of PID cases [1]. TOAs typically occur when PID evolves into an inflammatory mass. Although Chlamydia trachomatis and Neisseria gonorrhoeae are rarely isolated from TOAs, they may facilitate the invasion of the upper genital tract by the lower genital tract flora, increasing the risk of progressive infection [2]. Previously, multiple case reports and case series have reported on the occurrence of TOA in non-sexually active (NSA) female adults as well as in pediatric populations [1,3–11]. However, only one such case has been reported in Saudi Arabia [11].

TOA can be misdiagnosed and mismanaged in NSA women because the clinical presentation varies, and the pathogenesis is unclear. Probable causative factors include ascending lower genital tract infections, urinary tract infections, translocation of gastrointestinal tract infections, and infection with a virulent organism, with bacteremia/septicemia, leading to peritonitis and seeding of the infection in the ovary [12]. However, TOAs caused by bacterial spread from appendicitis or other bowel diseases can result in polymicrobial infections [7]. The incidence of PID complicated by TOA in NSA females remains unclear [1]. The clinical presentation of TOA and its relationship with complicated and ruptured diverticulitis of the colon have been reported in the literature [13]; however, ruptured appendiceal diverticulitis is considered rare and has not been reported yet in association with TOA [10,12,14].

Case Report

We present the case of a 25-year-old nulliparous woman who had been referred from the adult emergency department with a history of lower abdominal pain, sudden-onset on-and-off cramping, nausea, vomiting, and lightheadedness. Her gyneco-logical history was unremarkable, and she denied having menstrual disorders or recurrent vaginal discharge. The patient was single and had no history of sexual contact. Her medical history included a gastric sleeve 5 years before the present visit, for weight reduction, and treatment for depression. Initial vital signs were normal, and abdominal examination revealed tenderness in both lower quadrants. Sonography revealed a mildly enlarged right ovary that had deviated to the midline with preserved vascularity (Figures 1, 2). The probability of torsion/detorsion was suggested; hence, the treatment plan included admission and a diagnostic laparoscopy; however, the patient was discharged against medical advice. Two days later, the patient presented with fever, abdominal guarding, and persistent severe lower abdominal pain. She also reported a single diarrheal episode. Complete blood count showed white blood cell count: 1425 cells/µL, hemoglobin: 7.0 g/dL, mean corpuscular volume: 58.3 fL, mean corpuscular hemoglobin concentration: 28.3 g/dL, neutrophils: 1025 cells/µL, and platelet count: 353 000 cells/µL. Urinalysis was negative for nitrate, leucocytes, blood, and bacteria. Results of repeat pelvic ultrasonography revealed findings similar to the previous ultrasound, suggestive of ovarian torsion. Further imaging studies, including transrectal ultrasound and computed tomography (CT), were omitted preoperatively because the patient was already misdiagnosed with ovarian torsion, with the possibility of ongoing ovarian necrosis. The patient was admitted and underwent an emergency diagnostic laparoscopy.

The intraoperative findings included an enlarged right ovarian abscess that was frail and adhered to the bowel, as well as adherent bowel loops on the posterior uterine wall. Further, visualization of the left ovary was incomplete due to adhesions. Microbiological swabs were collected from the right ovarian abscess. The right ovarian abscess was drained and washed. The clinical picture was suggestive of PID; hence, a postoperative antibiotic regimen (ampicillin, clindamycin, and gentamycin) was initiated according to the guidelines. Owing to this uncommon finding in an NSA woman, the literature was reviewed, and the possibility of bacterial translocation from the bowel to the genitourinary system was considered. Postoperative CT (Figures 3–5) revealed the likelihood of complicated appendicitis with perforation and abscess formation. Clinically, abdominal pain was mildly relieved postoperatively. The radiologist, gynecologist, and general surgeon all recommended a repeat laparoscopy. The radiological diagnosis was confirmed intraoperatively, and an appendectomy was performed. The appendiceal abscess was drained and evacuated. The patient showed significant health improvement and was discharged on the 5th day following the operation.

The causative organism was Streptococcus constellatus, isolated from the intraoperative specimen. Urine and blood cultures obtained on admission were negative for any microorganism. The antibiotic therapy was changed to metronidazole and ceftriaxone. The histopathology report following laparoscopic appendectomy showed features consistent with a ruptured appendiceal diverticulum, which was associated with chronic active diverticulitis, with perforation, peri-appendicitis, and foreign body reaction.

Discussion

PID refers to an acute and subclinical infection of the upper genital tract involving any or all of the following: uterus, fallopian tubes, and ovaries. It is often accompanied by involvement of the neighboring pelvic organs. This results in endometritis, salpingitis, oophoritis, peritonitis, perihepatitis, and/or TOA. TOAs complicate approximately 30% of PID cases; they occur mostly in sexually active women, are usually polymicrobial, and are a form of sexually transmitted disease. N. gonorrheae and C. trachomatis are rarely isolated, but they might facilitate the invasion of the upper genital tract by the lower genital tract flora, increasing the risk of progressive infection [5].

Although TOAs are uncommon in NSA women, several case reports and case series have nevertheless been published in the literature. The mechanism remains unclear; however, multiple factors can contribute to the development of TOA in this population, including ascending infection of the genital tract due to vaginal voiding secondary to obesity, recessed urethra or concomitant urinary tract infection, gastrointestinal tract translocation, congenital genitourinary anomalies [1,6], and bacteremia and septicemia leading to peritonitis, serositis, and subsequent infection and abscess formation [12].

Gastrointestinal tract or bowel translocation occurs when viable bacteria pass through the gastrointestinal tract wall to extraintestinal organs, such as the ovaries and fallopian tubes, even without bowel perforation or a ruptured appendix. Intestinal bacterial overgrowth is associated with decreased host immunity. In addition, increased permeability of intestinal mucosal barriers secondary to surgery, bowel obstruction, and chronic constipation can all contribute to this translocation [6].

Acute or chronic appendicitis and appendectomy (7–9) have been associated with the development of TOAs in NSA female patients. Additionally, during menstruation in adolescents, the fallopian tubes secrete more nutrients and hormones in the presence of adhesions or active appendicitis, which may lead to the development of TOAs [7]. Furthermore, in a developing vaginal microbiome, an imbalance in the vaginal flora can lead to disruption, and a change in the bacterial replicative and pathogenic capabilities may trigger the infection. Vaginal flora may also be altered by recent intake of antibiotics [3]. Organisms such as Escherichia coli, Bacteroides fragilis, other Bacteroides spp., Peptostreptococcus, Peptococcus, and aerobic Streptococcus have been identified as causative agents of TOA [2].

In our patient, there was a possibility of a preceding appendiceal pathology that led to TOA. A single organism, S. constellatus, was isolated from the TOA. While this finding of a single organism in a TOA is rare, nevertheless, a few case reports have reported single organisms in TOAs (Table 1) [8,15–17]. A limitation of our study is that a quantitative polymerase chain reaction (qPCR) was not performed to obtain a precise result, and no culture was obtained from the peri-appendiceal abscess.

S. constellatus, a Gram-positive bacterium which belongs to the Streptococcus anginosus group, was isolated. These bacteria are considered commensal organisms found in the oral, gastrointestinal, and urogenital flora, and have rarely been isolated as pathogenic organisms in immune-competent patients. Several case studies have reported the ability of S. constellatus to form abscesses and disseminate to other locations in the body, leading to rare occurrences of peritonitis, TOA, subsequent septic emboli, septic thrombophlebitis, and septic shock [15]. Our patient was febrile only on admission, and only a single set of blood culture tests was obtained, which yielded negative results.

The histopathological findings of acute diverticulitis mimic the clinical presentation of acute appendicitis, and it is usually diagnosed postoperatively. The incidence of appendicular diverticulitis is considered rare, ranging between 0.014% and 1.9%, and reaches approximately 2.1% [14]. Risk factors are male sex, age >30 years, chronic appendicitis, cystic fibrosis, and Hirschsprung’s disease [18,19]. AlAli et al reported 5 cases; in 2 of these cases, the patients were young and female [20]. Preoperative CT imaging might aid in the diagnosis [20]; however, in our case, the appendiceal diverticulitis led to perforation and subsequent infection of the adjacent organs, including the inner female genital tract, leading to PID and abscess formation.

Misdiagnosed TOAs or those complicated by diverticulitis have been reported previously [13]. If diagnosed early, TOA and acute diverticulitis can be managed with a broad-spectrum antibiotic; however, severe cases require surgery [13].

Management of PID commences with prompt broad-spectrum antibiotic administration (eg, ceftriaxone 1 g i.v. every 24 hours, doxycycline 100 mg orally or i.v. every 12 hours, metronidazole 500 mg orally or i.v. every 12 hours), followed by interventional radiology for assisted percutaneous drainage, and subsequently, surgery.

Data on the treatment options for TOAs in the absence of sexually transmitted organisms are limited [6]. Due to the rarity of TOAs in NSA women, diagnosis can be challenging and time-consuming, as it might require extra imaging modalities and laboratory tests, resulting in delayed treatment and intervention.

Conclusions

TOA in NSA women should be considered as a differential diagnosis, with the possibility of infection with an atypical organism. Broad-spectrum antibiotics or multidrug therapy should be administered promptly to avoid long-term complications such as infertility. When suspicion is raised, an imaging study with a broader view to detect pathology of other organ systems preoperatively is recommended. Lower abdominal pain in young female patients still poses a diagnostic dilemma and should be investigated; however, when the presentation suggests a gynecological emergency, the timeframe can pose challenges.