Intracytoplasmic hyaline globules in the adrenal medulla of laboratory animals

Intracytoplasmic hyaline globules were found frequently in chromaffin cells of the adrenal medulla from several species of laboratory animals that died from various causes. The globules stained intensely red with PAS, were weakly acid-fast, did not stain with oil-red O and showed bright yellow autofluorescence. Ultrastructurally, they were finely granular, round to oval, intensely osmiophilic and were surrounded by an intimately bound trilaminar membrane. The globules were interpreted as aggregated secretory granules that occur in degenerating cells.