25–30% of all cases are related to monogenic hereditary tumor syndromes including multiple endocrine neoplasia 2 (MEN2), von Hippel-Lindau syndrome (VHL), neurofibromatosis type 1 (NF1) and the group of PGL syndromes caused by mutations in genes encoding succinate dehydrogenase (SDH) subunits and associated factors [2,3]. The gene discussed is NF1; the disease is von Hippel-Lindau disease.