Studies on quantitative morphology. VI. Morphometry of colloid and epithelium in the thyroid gland.

The colloid and epithelium percentages in the thyroid gland are characterized by a noticeable variability and a zonal heterogeneity; in the border region an enriching of the colloid component is observed and in the central part a higher epithelium concentration. Studies with different net point distances and measuring areas led to the following conclusions: provided that a sufficient number of points are attached, a distance of 250 micrometers may be used for common tests; the prolongation of the measuring time for lower distances than 100 micrometers is often not accompanied by an essentially better accuracy. Measuring areas should not be too small, even between fields of 20 mm2 differences of the few per cents may be observed in the same slide. The polynomial regression curve for the comparison of epithelium and colloid data seems to be influenced by the interstitium values: up to about 30% colloid an increase of the epithelium values is seen, since a further growing of the colloid percentages is connected with a decline of the epithelium percentages.