Abdominal Pain: An Omental Occasion: Presidential Poster

Abstract

A 45-year-old woman with no significant medical history presented with two days of right upper quadrant (RUQ) pain. The pain started as vague, diffuse abdominal discomfort but progressed to severe RUQ pain that worsened with inspiration, movement and food intake. Bowel movements were unchanged. On initial examination she was afebrile with normal vital signs. Abdominal exam revealed RUQ tenderness and positive Murphy's sign. Blood work was significant for WBC of 20,200/mm (83% neutrophil), total bilirubin 1.0mg/dL, and direct bilirubin 0.2mg/dL. Abdominal ultrasound demonstrated a mildly enlarged liver without focal masses or nodularity and normal gallbladder; CT abdomen was initially unremarkable. The severe RUQ pain persisted; MRCP revealed stranding and edema in omental fat at the dome of the liver and small right pleural effusion. The patient was treated with analgesics with subsequent resolution of her pain. Omental infarction, until recently, has been an elusive diagnosis in patients presenting with abdominal pain because of its relative rarity and nonspecific clinical presentation. A result of vascular compromise, omental infarction typically presents with sudden-onset right lower quadrant abdominal pain without fever or gastrointestinal symptoms. Secondary infarction is caused by omental torsion, thrombosis from hypercoagulopathy or vascular abnormalities. Idiopathic infarction may be related to obesity, heavy food intake, local trauma or use of laxatives. Imaging findings on ultrasound or CT include a focal area of increased echogenicity in the omental fat or as fat stranding and swirling of omental vessels. Radiographic diagnosis of omental infarction is critical as laparoscopic evaluation can be avoided. Abdominal pain from omental infarction is often managed conservatively with analgesics and anti-inflammatory drugs due to the self-limited disease course. However, a standard treatment modality has yet to be established. Rarely, persistent pain, bleeding, adhesions or abscesses may develop and require surgical intervention.Figure 1Figure 2This patient, with no known abdominal pathology or risk factors, had an atypical presentation of a rare clinical disease, in which imaging was paramount for diagnosis. There have been no reported cases of omental trapping in the liver dome and thus is a newly reported mechanism of infarction. The abdominal pain was initially attributed to hepatobiliary disease given location and thus multiple imaging modalities were utilized before a final diagnosis was made. In patients presenting with acute abdomen, regardless of location, omental infarction should remain on the differential as it may minimize diagnostic imaging and avoid surgery.