Pheochromocytoma
Image Description
This case shows nests and clusters of tumor cells with abundant dense amphophilic cytoplasm separated by a highly vascular stroma. The cytoplasm is granular due to the presence of membrane-bound, electron-dense secretory granules containing catecholamines. The nuclei are round or oval with one or more prominent nucleoli. Some of nuclei show degenerative atypia consisting of smudged chromatin.