Primary Omental Infarct: A Radiological Curiosity or a Real Disease?

Abstract

Primary Omental Infarction (POI) is a rare cause of acute abdominal pain. Patients may present with severe abdominal pain mimicking acute abdomen or could be completely asymptomatic. This large variation in presentation makes diagnosis confusing and challenging. Here we present two cases of omental infarction with very different presentations. A 25 year old woman who presented with right upper quadrant (RUQ) abdominal pain with radiation to her flank, exacerbated with any movement or cough. Her exam revealed severe tenderness over the RUQ. Lab work was remarkable for elevated transaminases (ALT: 122 U/L, AST: 93 U/L), ESR: 120 mm/h, CRP: 18mg/dL, CPK: 144U/L, WBC count of 15.5 k/uL. Her CT scan of the abdomen revealed right upper quadrant omental fat stranding with trace intrahepatic fluid representing omental infarct (OI). Her viral hepatitis panel and autoimmune panel were negative except for a low titer (1:40) antismooth muscle antibody. Liver inflammation from surrounding omental infarct was thought to be the etiology of elevated AST/ALT. Symptoms gradually improved with morphine. Patient was discharged home with down trending CRP (8.8 mg/dL) and liver tests (ALT: 62U/L, AST: 24 U/L). A 51 year old man with history of multiple sclerosis, presented with urinary retention, fever, diagnosed with urinary tract infection. He denied any abdominal pain. Lab work was remarkable for elevated transaminases (ALT: 76 U/L, AST: 67 U/L) and WBC count of 4.3 k/uL. His CT scan of abdomen with oral contrast revealed incidental finding of RUQ omental infarct. He was discharged home after treatment of infection. POI is a unusual disease with a wide variation in clinical presentation from asymptomatic imaging finding to severe abdominal pain requiring extensive work up and hospital admission. In acute cases it can be misconstrued with acute appendicitis, pancreatitis, and peptic ulcer disease. A diagnosis of primary OI is made when no discernable etiology is found. Secondary causes for OI include hypercoagulability, vasculitis, and polycythemia. POI is commonly found in the right side of the abdomen. Sudden movement, violent exercise, and hyperperistalsis have been reported as causes of POI. CT scan is the diagnostic test of choice. In the absence of clinical deterioration, watchful waiting and pain control seems to be appropriate but laproscopy and omental necrosectomy might be necessary if the diagnosis is not clear by imaging or if there is no improvement in 48hours.Figure: Omental infarct below the liver in case1.Figure: RUQ omental infarct in case 2.