How is microscopy of pheochomocytoma?

Pheochromocytomas are composed of polygonal to spindle-shaped chromaffin cells and their supporting cells, compartmentalized into small nests, or Zellballen, by a rich vascular The cytoplasm of the neoplastic cells often has a finely granular appearance, highlighted by a variety of silver stains, because of the presence of granules containing catecholamines. Electron microscopy reveals variable numbers electron-dense granules, representing catecholamines and sometimes other peptides. They show positivity to NE markers (chromogranin A, Synaptophysine, CD56)