[The lesser omentum. Normal aspect and tumor pathology in ultrasonography and x-ray computed tomography]

The lesser omentum is a peritoneal partition that can be divided into two portions: superior or gastrohepatic ligament and inferior or duodenohepatic ligament, although differentiation is sometimes difficult. Ultrasound and CT scan imaging allowed perfect definition of vascular and glandular elements contained in the omentum, and normal morphology is described. Masses developing between the two leaves of which it is constituted usually project in front of adjacent vascular structures and/or prolonged into the liver hilum, and a fatty layer separates them from large prevertebral vessels. These different guidelines allow them to be distinguished from retroperitoneal celiomesenteric adenopathies. These expansive processes are almost always of glandular origin secondary to primary digestive, retroperitoneal, pelvic and even bronchial tumors. In contrast, primary tumors are rare in this region.