Fig. 3

a The tumor composed of papillary and anastomosing channel-like structures (hematoxylin and eosin × 100). b Diffuse staining for CD31 (immunohistochemical × 200)
a The tumor composed of papillary and anastomosing channel-like structures (hematoxylin and eosin × 100). b Diffuse staining for CD31 (immunohistochemical × 200)