Acute Epiploic Appendagitis Mimicking Ovarian Torsion: A Case Report Highlighting Diagnostic Challenges

Introduction

Acute epiploic appendagitis is a rare cause of acute abdomen, presenting with lower abdominal pain. The estimated incidence of epiploic appendagitis is 1.3% and it is 4 times more common in males [1]. It typically presents during the second to fifth decades of life [1]. It is widely described in the literature as a mimic of various abdominal pathologies, most commonly acute appendicitis and acute diverticulitis [1]. However, there is no published report of acute epiploic appendagitis presenting a challenging differential diagnosis for acute ovarian torsion.

Ovarian torsion classically presents with acute lower abdominal pain with associated nausea and vomiting. This case report demonstrates that acute epiploic appendagitis can present clinically as a mimic of the typical acute ovarian torsion presentation in female patients. An awareness of this differential diagnosis is vital due to the distinct medical versus surgical management, respectively, in these 2 conditions. This knowledge could reduce the incidence of unnecessary surgery in patients with this abdominal pathology.

Case Report

A 37-year-old woman presented with a 3-day history of left iliac fossa pain that began as an intermittent sharp pain, which gradually worsened to a constant pain. The pain was in the left iliac fossa, with no radiation. It was exacerbated by movement and could not be relieved by simple analgesia. The patient received 3 doses of opiates in the hospital due to ongoing severe pain. There were 2 associated episodes of vomiting. There was no vaginal discharge or bleeding. A systems review was otherwise negative.

The patient was multiparous, having had 3 live births and 1 additional pregnancy that was not carried beyond 24 weeks. She had a history of 1 previous caesarean section and no other surgical history. Her past medical history was significant for migraine. Her last menstrual period was 10 days prior to admission. This period was on time according to her regular menstrual cycle, with no change in her regular bleeding pattern. She was sexually active. She was not taking any hormonal contraceptives. She had no significant drug history and had an allergy to penicillin.

On examination, her abdomen was soft with no guarding. There was exquisite tenderness on palpation of the left iliac fossa despite the administration of opioid analgesia. No masses were palpable abdominally and bowel sounds were audible. A bimanual vaginal examination was performed, which confirmed tenderness in the left iliac fossa with no evidence of cervical motion tenderness or any palpable adnexal masses.

The patient was apyrexial and haemodynamically stable with a normal heart rate and blood pressure. Results of a full examination were otherwise normal. Blood results revealed no abnormalities, with a normal hemoglobin (150 g/L), platelet count (197×109/L), white cell count (7.2×109/L), and C-reactive protein (<4mg/L). The beta-hCG blood test was negative. Urinalysis was positive for ketones (+3).

Considering the patient history, examination, bedside investigations, and blood results, the working differential diagnosis was an ovarian torsion. The presenting concern of severe, unilateral, intermittent pelvic pain progressing to constant pain associated with vomiting is typical of ovarian torsion. Localized tenderness in the left iliac fossa supported this diagnosis. There was no evidence of a mass felt abdominally or on vaginal examination. However, absence of a palpable mass does not rule out the diagnosis of ovarian torsion. A presenting concern such as this, in a woman of this age, with a negative beta-hCG should always prompt suspicion of an ovarian torsion. Pelvic inflammatory disease may also be considered as a differential diagnosis, although it was less likely in this patient due to the absence of vaginal discharge, dyspareunia, and abnormal vaginal bleeding.

Because the patient presented over the weekend, there was no access to abdominal ultrasound, so a decision for diagnostic laparoscopy was made based on the high clinical suspicion of ovarian torsion. When diagnostic laparoscopy was performed, the ovaries were grossly normal bilaterally and a torsion of an epiploic appendage was found (Figure 1). A diagnosis of acute epiploic appendagitis was made. The lesion was excised and was sent for histology. The patient was managed postoperatively with analgesia and was discharged 2 days after admission. She was actively involved in the shared decision making surrounding her care and gave informed consent for her case to be published anonymously.

Discussion

Epiploic appendages are small outpouchings of peritoneum, usually found in the sigmoid colon, but they can occur along the length of the colon [2]. These appendages, which range from 0.5 cm to 5 cm in length, consist of adipose tissue and vascular structures [3]. Acute epiploic appendagitis can be caused by either torsion of the appendage itself leading to vascular occlusion or spontaneous venous thrombosis within the structure [2]. It occurs in both males and females, although there is a male predominance, and it is most common in the second to fifth decades of life [2]. As these anatomical structures are more abundant along the sigmoid and descending colon, the pain in acute epiploic appendagitis is usually localized to the left lower quadrant but can also be felt on the right. Beyond lower abdominal pain, symptoms can be varied, with occasional findings of abdominal mass, rebound tenderness on palpation, and, rarely, nausea or vomiting [2]. Patients are usually apyrexial and there is rarely elevation of inflammatory markers [4]. This clinical picture is relatively non-specific and is most commonly mistaken for acute diverticulitis or, occasionally, acute appendicitis [5].

Numerous case reports in the literature demonstrate that patients with acute epiploic appendagitis are often misdiagnosed with acute appendicitis or acute diverticulitis. One case report describes a 57-year-old man presenting with sharp right lower-quadrant pain with no associated symptoms or vital sign abnormalities [1]. This patient was managed as having suspected acute appendicitis, but laparoscopy showed a normal appendix with a necrotic epiploic appendage [1]. Similarly, a retrospective review describes 6 patients (4 females and 3 males) with lower left abdominal pain, which were investigated as suspected acute diverticulitis and another patient presenting with right-sided pain investigated as acute appendicitis [6]. Radiological investigation showed all 7 of these patients had acute epiploic appendagitis [6].

On abdominal ultrasound, acute epiploic appendagitis appears as a hyperechoic oval mass with a hypoechoic halo [4]. This mass is found at the site of maximal abdominal tenderness and is non-compressible [6]. Importantly, the mass remains fixed in its position throughout deep breathing and does not mobilize alongside the abdominal contents [6]. The computed tomographic (CT) appearance of the mass confirms its contents to be fatty, with fatty attenuation surrounded by a hyper-attenuated rim [6]. CT is a vital tool to diagnose this condition and concurrently rule out other abdominal pathologies and is the preferrable imaging modality for diagnosis of this pathology as ultrasound is both user-dependent and has less accuracy with increasing thickness of visceral fat [7].

Acute epiploic appendagitis has a self-limiting disease course and should be managed conservatively with analgesia [2]. Typically, a prescription of anti-inflammatory oral pain medication for 1 week is sufficient to relieve symptoms until resolution of the condition [3]. Surgical management of the condition is not indicated except in the rare case that the patient does not improve with medical management [3]. This management is notably distinct from the purely operative management of ovarian torsion.

Conclusions

It is important to be aware of acute epiploic appendagitis as a differential diagnosis of ovarian torsion and its distinguishing and diagnostic radiological findings on CT to avoid unnecessary surgery in patients with this diagnosis.