Stereology of liver biopsies from healthy volunteers.

The stereological model and the base-line data of normal human liver needle biopsy-specimens are presented. Four reference systems were introduced: 1 cm3 of liver tissue, 1 cm3 of hepatocyte, 1 cm3 of hepatocytic cytoplasm and the volume of an average "mononuclear" hepatocyte. The sampling was done at three levels of magnification (1,000 X, 5,000 X and 10,000 X). A lobular differentiation was not considered. The baseline data show strikingly small variations (s.e. less than 10%) within the individual biopsy specimen and within the group of four biopsies. There is no principal difference between human beings presented here, rats, mice and dogs. Only the mean individual volume of human hepatocytes is clearly larger than in rodents. The problems and limitations of stereological work on liver biopsy specimens are discussed.