It is well known that several mesenchymal entities driven by gene fusions including STAT6:NAB2 (hypoglycemia in 5% of solitary fibrous tumors), ETV6::NTRK3 (neonatal hypercalcemia in infantile fibrosarcoma/congenital mesoblastic nephroma), and EWSR1::CREB1 (hyper-Interleukin-6 in angiomatoid fibrous histiocytoma) are specifically associated with paraneoplastic phenomena [29]. This evidence concerns the gene ETV6 and Hypoglycemia.