Enzyme histochemical and electron microscopic study of a virilizing adrenocortical adenoma.

Enzyme histochemical and ultrastructural studies of a "dexamethasone-suppressed" virilizing adrenocortical adenoma and the attached cortex revealed that tumor cells showed little activities of some lysosomal enzymes and scarcity of lipofuscins and dense bodies of lysosomal type, forming a marked contrast to the cells of zona reticularis and the virilizing adenomas previously reported. The other findings of tumor cells, such as a pattern of activities of dehydrogenases including 3beta-hydroxysteroid dehydrogenase and the morphology of mitochondria, were those of reticularis cells. The findings showed that scantiness of lipofuscins did not rule out the possibility of adenoma producing adrenal androgen, dehydroepiandrosterone. Most of the tumor cells as well as reticularis cells were positive for alkaline phosphatase, the activity of which was interpreted as the effect of ACTH stimulation.