Central part of adrenal that arose from neural tissue (image A).
Rich in blood vessels.
Predominant cell is the chromaffin cell.
Neuroendocrine cell that produces catecholamines (epinephrine and norepinephrine).
Has brownish appearance with chromium salts due to oxidation of catecholamines to melanin (hence the name "chromium" + "affinity").
Columnar cells with basophilic (bluish) granular cytoplasm arranged in clusters usually around vessels (image B).
Expresses synaptophysin and chromogranin.
Few ganglion cells are also present.
Large round or polygonal cells with abundant cytoplasm, large nuclei and prominent nucleolus (owl's eyes nucleus).