ATF1 and histiocytoma, Angiomatoid fibrous: As compared to their soft tissue counterparts, extrasomatic AFH occur in older patients (median age 35 versus 20-year-old), with a higher frequency of systemic symptoms (30% versus 10–15%), larger tumors, higher rate of recurrence (33% versus 11%), and a higher frequency of ATF1 as fusion partner (63% versus 19%) [9].