NF1 and malignant peripheral nerve sheath tumor: The lifetime risk of a malignant peripheral nerve sheath tumour (MPNST) in patients with type-1 NF1 deletions is in the range of 16–26% (De Raedt et al. 2003; Mautner et al. 2010) which is higher than the estimated lifetime risk for an MPNST in all NF1 patients which is 8–15.8% (Evans et al. 2002, 2012; Uusitalo et al. 2016).