CD99 and solitary fibrous tumor: The immunohistochemical study revealed that most tumors showed diffuse and intense reaction for specific diagnostic markers of solitary fibrous tumors, namely STAT 6 (n = 26, 100%), CD34 (n = 25, 96%), Bcl2 (n = 26, 100%) and CD99 (n = 21, 81%) and were negative for S100 protein and desmin in 100% of cases.