Figure 1

Histological features. A) The tumor was demarcated from the surrounding tissues with a relatively clear boundary (40×). B) The tumor showed striking floret-like giant cells and stromal myxoid change in the background (200×). C) The floret-like giant cells (arrow) had radially arranged nuclei and showed striking nuclear atypia (400×). D) Irregular rope-like collagen was arranged in the diffuse myxoid stroma (400×). E) Hypocellular bland spindle-shaped cells were uniform with hyperchromatic nuclei and inconspicuous nucleoli (400×). F) Atypical cells (arrow) were scattered in the background (400×). G) A few small or intermediate-sized, thick-walled vessels were observed (200×). H) Focally, the plexiform vascular pattern was also observed in this case (200×).