CLINICAL SEMINAR Cirrhosis: Morphologic Dynamics for the NonMorphologist

Cirrhosis is an irreversible end-stage liver disease characterized by septate scars dividing a distorted liver into nodules. It generates through a se-quence of dynamic changes and once it develops, it may alter its ap-pearance through variations in secondary factors, such as injury and nutrition. The different classification schemes have, unfortunately, only served to make cirrhosis static in our thinking. Stationary morphologic characteristics are of value only if they can be correlated with etiology. In the simplest sense, cirrhosis is a diffuse, irreversible late-stage chronic liver disease characterized morphologically by septate scars separat ing nodules of liver parenchyma, severely distorting its architecture (Figure 1), and clinically, by aberrations involving hepa-tocellular function and the hepatic vascular system. The most complex aspect of cirrhosis is its definition, h is both a clinical disease, ap-pearing as a sequence of changing physical phenomena, nd a histologic disease recognized as a static entity viewed at a given point in time. Yet these two views do not always coincide. This lack of agreement, between clinicians and pathologists about the meaning of cirrhosis is the result of several factors. First; morphol-ogists tend to hold to rigid criteria for their diagnosis of cirrhosis. Generally, they demand that there be both septate scars, criss-crossing the hepatic parenchyma, nd regenerative nod-ules of residual iver tissue. Both of these will be defined in more detail shortly. However, there are chronic hepatic diseases which may present with clinical features of cirrhosis and yet, when samples of these livers are viewed microscopically, the previously mentioned rigid criteria of histologic irrhosis may not be ful-filled. Thus, there may be clinical cirrhosis without morphologic irrhosis (F igure 2)