Fig. 5

Pathological findings. Hematoxylin and eosin staining of the tumor showed monotonous spindle cell proliferation without atypia. The mitosis rate was low (2/10 high-power fields). Immunohistochemical staining demonstrated that the tumor cells were positive for CD34, CD99, Bcl-2, STAT6, and vimentin, consistent with a diagnosis of solitary fibrous tumor