Microcalcifications as seen in epoxy-embedded carotids using a trichromic staining

Atherosclerotic plaques that undergo rapid progression to stenosis are responsible of stroke or acute coronary syndrome. The vulnerability of the atherosclerotic plaque may be enhanced due to the presence of microcalcifications. Our aim was to analyze microcalcifications on epoxy resin-embedded semithin sections from bioptic samples of carotid endarterectomies. An original trichromic method consisting of methylene blue, azur B, basic fuchsin and alizarin red was used. Particular attention was given to the discrimination of calcifications with a diameter 0,5 mm are clearly recognizable. In conclusion, in spite of their reduced size, microcalcifications can be clearly distinguished from the extracellular matrix. This trichromic method is thus reproducible and allows an easy identification of microcalcifications during the morphological analysis of atherosclerotic plaques.