Figure 3

Microscopic features. A &B, Hyperchromatic and pleomorphic spindled cells surrounding staghornlike blood vessels (A,×100 original magnification; B, ×200 original magnification. C, Tumor giant cells (arrow, ×400 original magnification). D, Abnormal mitoses (arrow, ×1000 original magnification). E, Tumor necrosis (N) (×200 original magnification). F, sporadic mature adipose tissue (×400 original magnification). Adipose cells showed S-100 immunostaining (inset, ×400 original magnification). G, Storiform arrangements of spindle cells in fibrous stroma containing dense collagen fibers (×400 original magnification). H, Haphazard arrangements of multinucleated floret-like cells in a loose myxoid stroma (×400 original magnification).