Introduction Even before von Recklinghausen's original monograph, in 1882,1 the literature has contained references to various bone changes complicating neurofibromatosis, e. g., bowing and pseudarthroses,2 disorders of growth.3 Indeed, Wilson4 includes bone affection in his definition of the syndrome, and Saville et al.5 state that neurofibromatosis is characterized by lesions of skin, nerve, and bone. Diverse secondary features other than bony which are said to occur can be grouped into psychological and endocrine. Regarding the former, perhaps the most pertinent comment is made by Wilson,4 "that some sufferers from a disease marked by unsightly deformities and disfigurements, especially when the face is concerned, should become sensitive, despondent or misanthropic need occasion no surprise." Authors further reflect that of diverse psychical disorders reported in connection with the malady none is specific and most are purely incidental. Various investigators, including Preiser and Davenport 6 and Yakovlev and Guthrie,7 have reported an increased