[Histological changes in liver tissue in cholestasis]. / Histologische Veränderungen des Lebergewebes bei Cholestase.

Cholestasis is a combination of defined clinical, paraclinical and morphological findings of which icterus is the direct symptom. It is the consequence of the delay or detention of the bile flow. By means of light microscopy different changes can be observed in hepatic tissue: formation of biliary thrombi, intracellular deposition of biliary components, ductal cholestasis with dilatation of the bile-duct lumina and applanation of the bile-duct epithelium, ductular proliferates and furthermore inflammatory mesenchymal reactions with cholangiolitis and cholangitis. These changes strengthen in dependence on the intensity and duration of the existing cholestasis. Bile lakes, bile extravasates, and biliary infarctions may occur in the process. The differentiation between intrahepatic non-mechanically and (extra-)hepatic mechanically conditioned cholestasis is of clinical importance. In the former the production and secretion of bile is disturbed (hepatosis, hepatitis and others), in the latter the extrahepatic bile ducts are above all affected: the bile flow is disturbed by stenosis, compression and obturation. The differentiation between the two kinds of cholestasis is impossible in the first three weeks because both of them develop identical lesion patterns. Distinguishable changes occur only after that. Consequently, findings from liver biopsy can only be a statement of probability. Reliable differentiation between the two kinds of cholestasis is however possible by means of modern technical methods for diagnostic purposes.