[Solitary fibrous tumor/hemangiopericytoma of central nervous system: a clinicopathological analysis of 60 cases].

Objective: To investigate the clinical manifestations, imaging features, clinicopathologic features, and differential diagnosis of solitary fibrous tumors/anginoblastomas (SFT/HPCs) originating in the central nervous system. Methods: Sixty cases of SFT/HPCs originating in the central nervous system were collected at Nanjing Jinling Hospital, from January 1, 2008 to December 31, 2016. The clinical data, imaging data, histomorphologic changes and immunohistochemical finding were analyzed in the sixty cases. Results: The 60 cases included 26 males and 34 females, aged 14 to 85 (median 49) years. The main clinical manifestations were headache, dizziness with nausea and vomiting. Radiologically, the tumors were large, enhancing, solid and cystic masses attached to the dura. Histopathologically, the neoplasms were composed of spindle cells with oval nuclei, inconspicuous nucleoli and moderate amount of eosinophilic cytoplasm arranged in fascicles with areas of hyalinized stroma, myxoid changes and a staghorn vascular pattern. Immunohistochemically, tumor cells of all cases were positive for vimentin (100.0%, 60/60), STAT6 (98.3%, 59/60), CD34 (61.7%, 37/60), and the tumor cells were typically positive for CD99, bcl-2, EMA and SSTR2 as well.Negative for S-100 protein, SOX10, E-cadherin, GFAP. Ki-67 index ranged from 1% to 50%. Forty cases were followed up for 6 to 82 months with average of 40 months, 30 patients were alive and 10 patients died. Conclusions: Central nervous system SFT/HPCs can be aggressive and relapses may occur several years after diagnosis. STAT6 is highly sensitive and specific for the diagnosis. Complete tumor resection is optional treatment followed by radiotherapy and chemotherapy. There is a correlation between the prognosis and the location of the disease, the histological grade, Ki-67 index, and fusion gene variants.