Uncommon Cause of Right Upper Quadrant Pain: A Case Report of Omental Infarction

Abstract

Introduction: Omental infarction is a rare cause of acute abdomen, which can mimic other common causes of acute abdomen. The incidence rate of omental infarction is less than 4 cases per 1,000 cases of appendicitis. Here, we report a case of idiopathic omental infarction in a 63-year-old female who presented with acute abdomen in the epigastric and right upper quadrant regions. Case Report: A 63-year-old female with history of diabetes, hypertension, and appendectomy presented to emergency room (ED) with a 5-day history of increasing epigastric pain. She denied any diarrhea, fever, constipation, hematochezia, or dysuria. She reported 2 episodes of non-bilious, non-bloody emesis. Physical exam showed an obese woman with BMI 34.2 kg/m2. She was afebrile with BP 129/67mm Hg, HR 74 min. Abdominal exam revealed a non-distended obese abdomen with tenderness in the right upper quadrant without guarding or rigidity. Labs showed normal CBC results with WBC 6100/mcL and normal lipase and liver function test. Ultrasound was done and showed hepatosteatosis and mild adenomyomatosis of the gall bladder fundus. Subsequently, CT scan of abdomen and pelvis with contrast was done and revealed a 6.2-cm ovoid, heterogeneous fatty lesion extending from the greater omentum superiorly with induration of the surrounding fat most consistent with an omental infarction. Patient was managed conservatively with pain control and hydration. She was discharged on the second day of admission and was scheduled for follow-up with gastroenterologist. Discussion: Omental infarction is a rare cause of acute abdomen. It presents predominantly in the right side, typically in the right iliac fossa. However, few cases of omental infarction presenting with right upper quadrant pain have been reported in literature, as in our patient. High body mass index (BMI) is believed to be related to fatty accumulation in the omentum and precipitates torsion. CT scan is the imaging of choice to help with diagnosis and rule out underlying pathological masses or cysts. It typically shows heterogeneous fatty lesions with hyper attenuating fatty streaks and a fluid cavity, depending on the degree of necrosis. Most patients are treated successfully with a conservative approach. In complicated cases with worsening of symptoms, surgical intervention is needed and allows for a definitive diagnosis and treatment with necrotic omentesectomy.Figure 1