Immunohistochemical staining of GCAB. A. Vimentin-positivity throughout the tumor. B. SMA-positivity in perivascular cells of the well-developed vessels and basement membrane. C. CD68-positivity was strong in the giant cells, weak in some oval-to-spindle tumor cells. D. CD34-positivity in the oval-to-spindle tumor cells and the monolayered small channels, but not in the giant cells. (Magnification: A, B, and D: 40× C: 20×).