A Small Glomus Tympanicum Tumor Resected by Minimally Invasive Transcanal Endoscopic Approach

Figure 3

Histopathology. Hematoxylin–eosin staining: (a) reticular vascular-rich round tumor (×40) and (b) round tumor cells were aggregated showing ribbon-like (arrow) and island-like (arrow head) formations in vascular spaces (vascular spaces were lined by endothelial cells (×200)). Immunohistochemical staining (×400): (c) α-smooth muscle actin (α-SMA) was negative, (d) synaptophysin was positive, (e) S-100 protein was positive on sustentacular cells, (f) cytokeratin AE1/AE3 was negative, and (g) neuron-specific enolase (NSE) was positive.