“…14,15 In 2007 the World Health Organization differentiated SFT and hemangiopericytomas (HPC) as two different entities, but on 2016 it was demonstrated that both shared a genetic mutation in which a 12q13 inversion occurred that merged NAB2 and STAT6 genes, generating a nuclear expression of STAT6 identifiable by immunologic studies, so nowadays both entities are recognized as one, the Solitary Fibrous Tumor / hemangiopericytoma (SFT/HPC). 16 As described before, SFT are rare, representing just 1-2% of all soft tissue tumors, and it has an incidence of 0, 35 for each 100.000 habitants. 10,12 Because of their slow growth, a parapharyngeal location can become symptomatic when the tumor reaches up to 2,5cms.…”