Figure 2: The resected tumor (a) and histological examination with HE (hematoxylin and eosin) staining (b and c) (Low magnification and high magnification) and immunohistochemistry (d-l). HE staining displayed a defined nest consisting of cells surrounding fibrovascular substances. Immunohistochemistry showed tumor cells are positive for CD56 (d), Syn (e), CgA (f), and PAX-8 (g). Diffuse positivity for CK (h). The tumor cells were negatively stained for RCC (i), Melan-A (j), and HMB45 (k). Sustentacular cells and tumor cells were negative for S-100 (l)