RET and multiple endocrine neoplasia type 2B: Intestinal ganglioneuromatosis has been reported in the context of neurofibromatosis type 1 (NF1), often with diffuse or plexiform involvement, Cowden syndrome (mutation in PTEN gene), typically with ganglioneuromatous polyposis and multiple endocrine neoplasia type 2B (RET mutation), and usually with diffuse gastrointestinal involvement [3,4,7,18,19,20,21,22].