Fig. 4

Nests of rounded epithelioid tumoral cells with marked nuclear atypia surround capillary-sized vessels (hematoxylin and eosin stain, ×200) (A). The tumor shows marked nuclear atypia and high grade of mitotic activity (pointed to by the blue arrow)and atypical mitotic figures (pointed to by the green arrow) (hematoxylin and eosin stain, ×400) (B)