A case of intracranial solitary fibrous tumor/hemangiopericytoma with dedifferentiated component.

We report the case of a 51-year-old Japanese man with an intracranial dedifferentiated solitary fibrous tumor/hemangiopericytoma (SFT/HPC) identified morphologically and immunohistochemically, comprised of a typical SFT/HPC with a high-grade pleomorphic component. NAB2-STAT6 fusion transcripts were detected by reverse transcriptase polymerase chain reaction in both the conventional and high-grade components. The tumor cells in both components showed the nuclear expression of STAT6 protein, indicating the diagnostic value of these examinations. Intracranial dedifferentiated SFT/HPC is a very rare but important differential diagnosis in intracranial pleomorphic tumors.