Ultrastructural and biochemical correlates of adrenal and extra-adrenal pheochromocytoma

The ultrastructure of a group of chromaffin neoplasms of adrenal medulla and extra-adrenal tissues has been studied with particular reference to delineation of chromaffin granule specificity and type catecholamine content. Extra-adrenal chromaffin tumors had high concentrations of norepinephrine which suggested a direct relationship to numerous electron-dense granular bodies in the cell cytoplasm. High or intermediate levels of epinephrine in tissue, on the other hand, were associated with cytoplasmic granular bodies of much less density. Comparison of the structural character of the neoplastic chromaffin cell and the normal adrenal medullary cell reveals variations in the extra-adrenal neoplasms but little in those of the adrenal gland. The differences consisted of extraordinary numbers and conformity of mitochondria and largely dense-cored granular bodies in the cytoplasm.