NF1 and Cowden disease: This heterogeneous group includes ganglion cells and nerve sheath tumors that have been frequently described as multiple lesions in association with inherited syndrome such as von Recklinghausen's (or type 1) neurofibromatosis (NF-1) [4,5], multiple endocrine neoplasia type 2B (MEN 2B) [6] and Cowden syndrome [7].