Figure 2.

Macroscopic findings and pathological features of the resected tumor. A: Gross findings of the resected specimen. The tumor was encapsulated and measured 3 cm × 1.5 cm × 1.5 cm; B: The paraganglioma comprised a dual cell population arranged in a characteristic nested Zellballen pattern (HE stain, × 400); C: Immunohistochemistory of Chromogranin A, × 400; D: Synaptophysin were strongly positive and confirmed a neuroendocrine origin, supporting the diagnosis of paraganglioma, × 400; E: The MIB-1 labeling index, × 400.