Ultrastructural finding in case of paraganglioma?

CAROTID BODY TUMOUR (CHEMODECTOMA, CAROTID BODY PARAGANGLIOMA). Carotid body tumor arises in the carotid bodies which are situated at the bifurcation of the common carotid aeries. Carotid bodies are normally pa of the chemoreceptor system and the cells of this system are sensitive to changes in the pH and aerial oxygen tension and are also the storage site for catecholamines. Histologically similar tumors are found in other parasympathetic ganglia represented by the vagus and glomus jugulare (jugulotympanic bodies). Grossly, they are small, firm, dark tan, encapsulated nodules. Microscopically, well-differentiated tumor cells form characteristic organoid or alveolar pattern, as is the case with all other neuroendocrine tumors. The tumor cells contain dark neurosecretory granules containing catecholamines. Ref: TEXTBOOK OF PATHOLOGY 6th EDITION - HARSH MOHAN PAGE NO:521