<prompt> Which of the following is the most characteristic ultrastructural feature of paraganglioma on electron microscopy?Shrunken mitochondriaLarge Golgi apparatusFrequent mitosesDense core neuroendocrine granules  <response>: Electron microscopy examination of paragangliomas show membrane bound electron dense neurosecretory granules in the cytoplasm of tumor cells. Ref: Head and Neck Surgical Pathology By Ben Z. Pilch, Page 68; Dail and Hammars Pulmonary Pathology: Neoplastic Lung Disease By Joseph F. Tomashefski, Page 533; Salivary Gland Diseases: Surgical and Medical Management By Robe Lee Witt. 