Abstract
A 78-year-old woman was admitted to our hospital because of her right upper abdominal pain. During her hospitalization, the abdominal pain deteriorated and peritoneal signs were observed. Then we attempted the emergency operation under a diagnosis of acute generalized peritonitis. Because the inflammatory mass lesion with the necrosis in the great omentum was revealed at the operation, partial omentectomy and abdominal cavity drainage were performed. A definitive diagnosis of primary omental abscess was made on the basis of the surgical and pathological findings, although no identifiable etiology was found.
