In pediatric age it is often associated with genetic syndromes such as Neurofibromatosis 1 (NF1), multiple endocrine neoplasia type 2B (MEN2B) and Cowden syndrome (PTEN mutation), and ganglioneuromas (GNs) may be sometimes the first sign of the disease. This evidence concerns the gene RET and multiple endocrine neoplasia type 2B.