Clinicopathological analysis of solitary fibrous tumor

Objective: The aim of this study was to investigate the clinicopathologic characteristics, diagnosis and differential diagnosis, molecular genetics, treatment and prognosis of solitary fibrous tumor (SFT). Methods: The clinicopathological manifestations were analyzed retrospectively in 22 patients with surgically confirmed SFT. Results: There were 12 male patients and 10 female patients, with the age range 33–67 (mean 48.62) years. The SFTs originated from different from parts of the body, including 13 in the chest, 2 in the lungs, 3 in the abdomen, 1 in the lumbosacral area, 2 in the pelvis, and 1 in the left shoulder. There were 19 benign and 3 malignant tumors. Major clinical presentations were local masses and compression symptoms. Microscopy: the tumor was composed of areas of alternating hypercellularity and hypocellularity. The tumor cells were spindle to short-spindle shaped and arranged in fascicular or storiform pattern and hemangiopericytoma-like structure was presented. Immunohistochemically, Vimentin positive rate was 100% (22/22), Bcl-2 positive rate was 95.5% (21/22), CD99 positive rate was 86.4% (19/22), CD34 positive rate was 81.8 (18/22), focally positive for P53, as well as negative CK, S100 and Desmin. Ki67 labelling index was 2%–30%. Conclusion: SFT is a rare tumor which may be found in various parts of human body. SFT mostly is a benign tumor, but a few could be malignant. Its diagnosis mainly rely on its morphologic features and immunohistochemical profiles. The major treatment is to completely resect it by operation and long-term clinical follow-up is necessary.