Ultrastructural changes of the adrenal cortex in Cushing's syndrome treated with aminoglutethimide (Elipten Ciba)

The main ultrastructural feature of human adrenal cortices following administration of aminoglutethimide (Elipten CIBA), a steroid biosynthesis blocking agent, is a striking intracellular accumulation of lipids, also seen in the light microscopy. The lipids accumulate in the adrenocortical cells but are also stored in the cytoplasm of pericapillary histiocytes. The lipids are present in the adrenocortical cells mostly as rounded liposomes of variable size, whereas those in the histiocytes usually show up as an amorphous debris with abundant myelin figures and cholesterol crystals. In some areas of the adrenal cortex activated histiocytes changing into lipophages may become the prevalent cell. They also take the place of destroyed adrenocortical cells and can form compact cell aggregates of variable size or even columnar strands between neighbouring capillaries, thus resembling columns of adrenocortical cells. In some of the adrenocortical cells focal cytoplasmic degradation, turning into coagulation necrosis, was observed. In others initial cytolysis was found. In contrast with earlier findings in experimental animals, mitochondrial changes in humans were not a prominent feature. The only changes occasionally observed were a focal disappearance of the vesicular cristae and a concomitant fibrillary loosening of the mitochondrial matrix.