Cell Types and Their Proportion in Pars Anterior of Adult Male Human Hypophysis.

Abstract

There is considerable disagreement on the number of distinct cell types in the anterior lobe of the hypophysis, as well as on the question of the relative number of each type under normal conditions. As many as 7 different kinds of epithelial cells have been described. How many of these are merely different functional stages of the same cell is not settled; but for practical purposes, at least 3 kinds can be regularly recognized by relatively simple technique. They are: chromophobe (chief, reserve, clear, undifferentiated, neutrophil), acidophil (eosinophil, oxyphil, alpha) and basophil (cyanophil, beta). The tendency seems to be to regard the acidophils as predominating and either the chromophobes or basophils as the fewest in number, although a few authors estimate that the chromophobes are the most numerous. An increase in the relative number of basophils in old age is also a widespread notion. It is obviously of prime importance to settle these questions in order to properly interpret abnormalities in the hypophysis, such as are now being reported frequently in the pathological literature. This is a preliminary report on a differential count of the cells in the anterior lobe of 100 human hypophyses from normal male adults, according to the method outlined in a previous communication. The only change introduced since then is to put the section first for about one-half minute in ordinary hematoxylin and washing well with distilled water before staining with Mallory's connective-tissue stain. Only cases of sudden and usually accidental death, in which the hypophysis was fixed within 12 hours after death, were used. They ranged in age from 18 to 78 years. The chromophobes represent on an average 52% of the total cells (from 34% to 66%). The scarcity of chromophobes, so often mentioned, is not substantiated, since they are normally never below one-third of all the cells. They are also the least variable, the coefficient of variation being 15. Many of these cells contain very little cytoplasm so that they do not appear as numerous as an actual count indicates.