A 6 year old male with no past medical history presented to the emergency room (ER) with six hours of right lower quadrant (RLQ) pain. The pain was described as sharp and non radiating. Patient denied any nausea, vomiting, diarrhea, dizziness, dysuria or fever but did complain of loss of appetite and pain upon walking.
Upon arrival to the ER patient had stable vitals, afebrile and in no acute distress. Patient’s physical exam was unremarkable apart from RLQ tenderness to palpation. The pain was described as seven out of ten and was elicited by jumping.
A workup in the ED included a white blood count (WBC) of 14.2K/mcL with segmented neutrophils of 74.8%. Surgery was consulted who performed a bedside ultrasound (US) which was inconclusive. Because of the history and the PE findings, patient was taken to the operating room (OR) for an open appendectomy and was found to have torsion of the omentum with a normal appearing appendix. The pathology report confirmed the diagnosis of torsed omentum with normal appendix. Patient was admitted to the inpatient floor for post-operative management and was discharged home after 24 hours of observation.
Omental torsion is an uncommon cause of acute abdominal pain, typically misdiagnosed pre-operatively as appendicitis. In children, it is estimated that 0.1% of the cases who underwent laparotomy for acute appendicitis were found to have omental torsion. Children present with complaints of right lower quadrant pain, without preceding periumbilical pain. Gastrointestinal symptoms such as anorexia, nausea, emesis or diarrhea are typically absent. Majority of children present without fever or elevated white blood cell count.
Primary omental torsion (POT) occurs when the omentum twists around its long axis causing venous obstruction, edema, and vascular compromise. Obesity in children is well described as a risk factor for the development of omental torsion. Furthermore, the higher accumulation of omental fat in males than females, with the same body weight, may explain the predominance of POT among male children; male to female ratio 4:1.
The lesion is often missed or mistaken in pre-operative imaging, for more common intra-abdominal processes. Ultrasonography shows a nonmobile, fixed hypoechoic mass within the omentum.
If confident diagnosis can be made with the clinical picture and imaging studies, some literature recommends conservative treatment with oral analgesics, anti-inflammatory drugs and prophylactic antibiotics as the first line of treatment for the first 24-48 hours. However, numerous reports show that early laparoscopic omentectomy is an appropriate treatment due to quick resolution of symptoms, short hospital stay, decreased use of narcotics and overall low risk of complications. Appendectomy is often done in conjunction with this surgical procedure to remove risk of appendicitis in the future.
Our patient had presenting symptoms, risk factors and workup consistent with prior reports of omental torsion. The patient was an obese male, presenting with complaints of RLQ pain; however, did not present with gastrointestinal symptoms typical of appendicitis. In addition, our patient was afebrile on presentation with normal white blood cell count. Primary omental torsion is an entity that mimics many acute abdominal pathologies and hence should be included in the differential diagnosis.
To cite this abstract:Nowroozi H, Aly A, Fox M, Volkin Y. Omental Torsion Mimicking Acute Appendicitis. Abstract published at Hospital Medicine 2015, March 29-April 1, National Harbor, Md. Abstract 422. Journal of Hospital Medicine. 2015; 10 (suppl 2). https://www.shmabstracts.com/abstract/omental-torsion-mimicking-acute-appendicitis/. Accessed November 13, 2019.