Quantitative analysis of nucleoli and nucleolar organizer regions in cultured primary human normal, reactive and malignant mesothelial cells

Summary The number and the size of silver-stained intranuclear granules, which correspond to the nucleolus and nucleolar organizer regions, have been determined by means of quantitative methods in cultured primary human mesotbelial cells obtained from normal, reactive and malignant mesotbelium. The mean values per nucleus of the number, the total area, the average area, and the relative area of the silver-stained granules and the mean nuclear area were determined for each of the three conditions. Normal, reactive and malignant mesotbelial cells differed significantly in all the features. These findings at the optical level reflect the differing rate of the nucleolar biosynthetic activity related to the different biological properties of the three cell types, and the features can be useful morpbometric descriptors in the diagnostic pathology of the mesothellum.