Ultrastructure of the adrenal cortex in Cushing's disease in children

Ultrastructural morphometry of normal adrenal cortex and of hyperplastic adrenals in gushing's disease

Surgical specimens of 4 normal adrenal glands and of 5 hyperplastic ones in Cushing's disease were studied ultrastructurally. The ultrastructure of the three zones of each adrenal gland was morphometrically and statistically analyzed. Comparing the statistical data of the three zones of the normal gland, the development of smooth endoplasmic reticuium and rough endoplasmic reticuium showed an increase from the outer zona glomerulosa to the inner zona fasciculata and reticularis. Also, the mitochondria were more numerous in the inner zona reticularis than in the outer zones. In Cushing's disease, the smooth endoplasmic reticuium, the rough endoplasmic reticuium, and the mitochondria were developed to a significantly higher degree than in normal human adrenal glands. The distribution of the cell organelles in the zona fasciculata and zona reticularis is almost alike in normal adrenal glands and in the adrenal cortex in Cushing's disease, except that the smooth endoplasmic reticuium in the zona reticularis was less extensive than in the zona fasciculata. The volume percentages of lipid vacuoies in the hyperplastic zona fasciculata in Cushing's disease was strongly and significantly decreased in comparison to normal adrenal glands. Our ultrastructural findings and the statistical data were in accordance with the results from animal experiments with adrenocorticotropic hormone (ACTH) stimulation and confirmed former qualitative ultrastructural findings concerning human adrenal gland changes in ACTH-dependent Cushing's disease.

Ultrastructural morphometry of different adrenal adenoma types

Twelve surgical specimens of adrenal tumors (3 mainly compact cell adenomas and 2 mainly spongiocytic adenomas of Cushing's syndrome, 4 adenomas of Conn's syndrome, 1 androgen-secreting adenoma, and 2 hormonally inactive tumors) were studied by ultrastructural morphometry, using the point-counting method. All groups were compared with regard to the statistical differences among the different cell organelles. Compact cell adenomas and spongiocytic adenomas in Cushing's syndrome revealed differences in the volume fraction of the following cell organefles: nuclei, smooth endoplasmic reticulum, mitochondria, Golgi zones, and unorganized cytoplasm, as well as in the fraction of lipid vacuoles. Compact cell adenomas in Cushing's syndrome were different from Conn's adenomas with respect to nuclei, smooth endoplasmic reticulum, rough endoplasmic reticulum, lysosomes, Golgi zones, and unorganized cytoplasm. Spongiocytic adenomas in Cushing's syndrome were different from adenomas in Conn's syndrome with respect to organized cytoplasm and lysosomes. Further data are given concerning the differences between Cushing's syndrome, adenomas in androgen-producing tumors, and inactive tumors. The statistically significant data were correlated with the functional expression of the different tumors. The morphometric studies confirmed the visually established ultrastructural features of adrenal tumors and provided further significant differences. Finally, these examinations obviously yielded specific patterns of the different adrenal adenoma types.

Androgen producing adrenocortical carcinoma

Two cases of androgen secreting adrenocortical carcinoma have been described by light and electron microscopy. The histological and ultrastructural features of the tumour cells were similar to those of compact cells of zona reticularis and to those described in virilizing adenomas. They possess numerous mitochondria with lamellar and tubular cristae, abundant smooth endoplasmic reticulum, lipofuscin bodies and scanty lipid. Irregularly shaped, crenated mitochondria, with outpouchings of the outer limiting membrane have also been observed. The clusters of neoplastic cells were surrounded by basement membrane which demonstrated a focal discontinuity, probably reflecting malignancy of the tumours. Hyperplasia of smooth endoplasmic reticulum and the presence of outpouchings of the mitochondrial outer limiting membrane might be the morphological manifestation of endocrine activity of the tumours.

Changes in the fine structure and function of a hormone-secreting adrenocortical tumour investigated in tissue culture

Tissue cultures of a surgically removed adrenocortical tumour causing Cushing's syndrome, and tissue cultures from the attached, tumour-free adrenal were studied. There were two cell types characteristic of tumour tissue. The cell type occurring most frequently had pronounced hypertrophied agranular endoplasmic reticulum. A fewer number of lipid-rich cells containing many electron-dense granules could also be found. The ratio of cells changed during cultivation. In the 17 days tumour culture, a higher percentage of lipid-rich cells could be observed. In spite of continuous ACTH treatment, the initially high hydrocortisone level decreased, gradually. It may be assumed that the lipid-rich cells are of reduced ability as regards hydrocortisone production.

A new crystal-containing cell in human adrenal cortex

Electron microscope examination of the adrenal cortex from three male human subjects revealed a special type of cell occurring in periendothelial spaces, in all adrenal cortex zones. It is a clear, spindle-shaped cell the principal cytoplasmic features of which are crystalline inclusions with a structure similar to that of the Reinke crystals of human testicular interstitial cells and an abundance of microfilaments. Enzymatic digestions with pronase, pepsin, and ribonuclease were performed, and no digestion of the crystals was obtained. The crystals had no peroxidase or acid phosphatase activities. This cell appears to be exclusive to human males and it may be related to adrenal androgen secretion.