Microscopic aspects of human liver pseudocapillarisation. Post-mortem (myocardial acute infarction) histology studies on paraffin-embedded sections (5 μm thick) of formalin-fixed liver tissue. Masson's trichrome staining shows the central vein and pericentral hepatocytes of young (A) and old liver (B) with perisinusoidal collagen deposition (blue staining). CD31 immunostaining of young (C) and old liver (D) with an increased sinusoidal protein expression. Magnification 20×.