NF1 and schwannomatosis: The interest for peripheral nerve sheath tumors is mainly due to the fact that these tumors can be diagnosed in the context of tumor-predisposing syndromes, such as neurofibromatosis type 1 (NF1) and related forms, NF2-related-schwannomatosis (formerly NF2) or SMARCB1/LZTR1-related schwannomatoses (formerly schwannomatosis) [1].