Herniation of Liver Through Esophageal Hiatus, Rat

Abstract

Herniation of a portion of a liver lobe through the diaphragm appears grossly as a well-defined smooth or slightly dimpled nodule on the diaphragmatic surface of the liver (Figs. 134, 135). The nodule is frequently the same color as the liver or may be darker or lighter depending on the degree of vascular congestion or hepatocellular alteration and fatty change. The nodule can vary in size and shape depending on the diameter and nature of the diaphragmatic defect, i.e., whether a direct opening is present (complete hernia) or whether the defect results from a weakening of the diaphragmatic fascia with formation of a hernial sac (incomplete hernia). Nodules protruding through a diaphragmatic opening, especially if accompanied by some degree of constriction, such as the example illustrated in Fig. 134, can generally be identified properly at the time of necropsy.