Knots in Your Stomach: The Challenge of Omental Infarction

Abstract

A 45-year-old woman with a history only of chronic lower back pain was admitted with sudden severe right upper quadrant abdominal pain. A similar episode occurred two months previously that resolved spontaneously. On exam, her abdomen was mildly tender and distended, and lungs were clear to auscultation. Laboratory studies were remarkable only for a leukocytosis of 14k/μL. No gallstones were found on abdominal ultrasound, and computerized tomography (CT) of the abdomen and pelvis revealed no acute pathology except for right lower lung atelectasis. Subsequently, the patient developed a productive cough and fever of 38°C. As the pain became increasingly severe and more pleuritic, a CT-thorax was performed to rule-out pulmonary embolus, incidentally revealing acute omental infarction (OI) anterolateral to the liver and a pleural infusion with infiltrate of the right middle and lower lung lobes compatible with pneumonia. Her pain then abruptly improved with conservative management, and the patient was started and subsequently discharged on antibiotic therapy. One month after discharge she remained free of abdominal pain and respiratory symptoms. The diagnosis of OI is usually delayed given its rarity. Patients with OI can undergo interventions as invasive as surgery before it is considered; our service was initially consulted by surgery for endoscopic retrograde cholangiopancreatography given concern for biliary pathology. This patient lacked several risk factors (male gender, cirrhosis, obesity) that are associated with an intermittently “upturned” omentum located between the abdominal wall and the anterior aspect of the liver. Her prior episode of abdominal pain and her initial presentation of right upper quadrant pain without CT findings suggests she may have been having intermittent torsion of an upturned omentum. With worsening torsion and vascular compromise, she developed frank infarction during her hospitalization. Continued irritation of the parietal peritoneum caused her to take more shallow breaths, resulting in atelectasis and then pneumonia. Conservative management is warranted in most cases of OI as it resolves on its own, as in this patient. This case reminds us to consider OI when evaluating abdominal pain, despite its rarity, given its response to conservative measures when working with surgeons in a multidisciplinary fashion. It also is, to our knowledge, one of the first reports of OI complicated by pneumonia.