Multiple pigmented adrenal cortical nodules associated with Cushing's syndrome. Histochemical, ultrastructural and...

Multiple pigmented adrenocortical nodules were found in a 25-year-old woman associated with Cushing's syndrome, whose laboratory data indicated that the adrenal cortex had been functioning autonomously and adrenocorticotrophic hormone (ACTH) from the pituitary gland as suppressed. The surgically removed left adrenal gland disclosed multiple black nodules measuring up to 3 mm in diameter and histologically consisting of large "compact cells" which contained numerous yellow-brown pigments, but adjacent cortical cells were not atrophied. This kind of adrenal lesion is generally regarded as nodular hyperplasia of the cortex. The present case revealed scanty lipid and markedly increased activity of 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) and glucose-6-phosphate-dehydrogenase (G6PD). Ultrastructural study showed abundant cytoplasm with a large number of mitochondria, well-developed smooth-surfaced endoplasmic reticulum (SER), less rough-surfaced endoplasmic reticulum (RER), lysosomes, and numerous granules in cells of the nodules. Mitochondria varied in size and shape up to occasional giant mitochondria. SER was vesicular or tubular forming a network of anastomosing tubules. Granules varied greatly in size from 400 millimicrons to 6 microns in diameter, with diverse electron densities, mostly exhibiting the structural features of lipofuscin. The ultrastructural features resembled those in black adenoma associated with Cushing's syndrome ever reported. Concentration of cortisol was increased in the tissue where numerous black nodules were contained.