Solitary fibrous tumour, NOS

**Definition:** Solitary fibrous tumour (SFT) is a fibroblastic tumour characterized by a prominent, branching, thin-walled, dilated (staghorn) vasculature and NAB2-STAT6 gene rearrangement. SFTs affect men and women equally and are most common in adults, with a peak incidence between 40 and 70 years.