Liver cell rosettes: structural differences in cholestasis and hepatitis.

Cholestatic and hepatitic liver cell rosettes, gland-like formations found respectively in chronic cholestasis and in chronic active hepatitis, represent structural modifications of liver cell plates in response to injury. Differences in cytokeratin expression, ultrastructure and three-dimensional (3-D) configuration have been investigated. Cholestatic rosettes are considered to be a form of biliary metaplasia of hepatocytes, linking with newly-formed bile ductules in adjacent septa and probably providing some protection from injury caused by abnormal bile constituents. Hepatitis rosettes, by contrast, are a form of liver cell regeneration developing in isolated surviving hepatocytes or small groups of hepatocytes within areas of collapse.