FINE STRUCTURE OF THE HUMAN ADRENAL CORTEX IN HYPERFUNCTIONING STATES

Abstract

The fine structure of the human adrenal cortex in hyperfunctioning states was investigated. Materials were taken during surgery from 6 patients with Cushing's syndrome, of which 2 were due to adrenal adenoma and 4 were due to adrenal hyperplasia, as well as from 7 patients with primary aldosteronism, in which every case proved to be due to adrenal adenoma. The specimens were fixed immediately after removal either in 2% osmium tetroxide or in 2.5-4% glutaraldehyde. The latter was followed by a postfixation in 2% osmium tetroxide. After dehydration the specimens were embedded in Epon epoxy resin. Thin sections for electron microscopy were made with glass knives on a Porter-Blum microsome, and stained with lead or with 1.0% uranyl acetate and lead to be examined with a Hitachi HS-7s electron microscope. The results are as follows:
(1) In the cases of Cushing's syndrome the specimens presented a wide variety of cellular fine structures both in adenomatous tissues and in zona fasciculata of the hyperplastic adrenal cortex. The structural changes were far more prominent in the former than in the latter. Some mitochondria in the adenomatous tissues resembled those which were found in the normal zona fasciculata, but others showed a wide variation in number, size, form and in the arrangement of cristae. The findings in the cases of adrenal hyperplasia differed from those in the cases of normal zona fasciculata. Mitochondria were irregular in form and in the arrangement of cristae. In one case of adrenal adenoma, occurrence of small electron dense bodies in the agranular endoplasmic reticulum as well as openings of the endoplasmic reticulum into the intercellular space was recognized. The significance of the dense bodies remained unknown.
(2) Simillar findings were obtained in all of the 7 cases of primary aldosteronism. The adenomatous cells in these patients were characterized by rich vacuoles and myelin figures. Mitochondria essentially corresponded in form and structures to those of the normal zona glomerulosa.
These findings indicated that in the hyperfunctioning states of the adrenal cortex, mitochondria presented a wide variety in their size, form and structure which could not be seen in the normal state. On the basis of the characteristic structures of mitochondria, it is suggested that the adenoma in Cushing's syndrome might be derived from the zona fasciculata whereas the adenoma in primary aldosteronism from the zona, glomerulosa.