Introduction
The word “cirrhosis” comes from the Greek kirrhos, meaning yellowish, tawny, and describes the gross pathology of the diseased liver. Since the late 1980s, however, clinicians have used the definition provided by the World Health Organization, which defines cirrhosis as a diffuse liver process where fibrosis has resulted in a conversion of the liver architecture into structurally abnormal nodules [1]. This distortion of liver architecture leads to compression of hepatic vascular and biliary structures, creating a further imbalance in the delivery of nutrients, oxygen, and metabolites. Even after the original insult has been controlled or stopped, the cirrhotic state persists. Although the causes of chronic liver disease encompass a wide spectrum of pathophysiological processes, cirrhosis is a common outcome [2].
Classification
Schemes for categorizing fibrosis and cirrhosis have been developed based upon gross morphology, microscopic histology (Figures 5.1–5.3), etiology, and clinical presentation. Categorization based upon gross morphology and histology has limited utility because it does not distinguish between the original pathogenic mechanisms of disease. The more commonly used pathologic staging systems (developed for the histopathologic description of the viral hepatitides), METAVIR and Ishak, stage fibrosis by varying degrees of presence of fibrosis, ranging from portal expansion to cirrhosis.