Clinicopathologic characteristics of solitary fibrous tumor

Objective To investigate the clinicopathologic characteristics and immunophenotype of the solitary fibrous tumor with emphasis on differential diagnosis.Methods Clinicopathological analysis of five cases of solitary fibrous tumor was performed with immnohistochemical study.Staining of CD34,CD99,vimentin,desmin,CD68 and S-100 protein was done by immunohistochemical SP method.Results Histologically the tumor was composed of fibroblast-like spindle cells,arranged in fascicles and storiform pattern.Tumor cells were strongly immunoreactive to CD34,CD99 and vimentin,while negative to desmin,CD68 and S-100 protein.Conclusion Most solitary fibrous tumors are benign tumors,and can be diagnosed by histological and immunohistochemical findings.When cytologic atypia,hemorrhage,necrosis and high mitotic activity are present,the solitary fibrous tumor may be malignant.