Penile neurofibromas

Unless omitted and underreported, penile neurofibromas are rare. Between Ja nuary 2, 1982 and December 31, 1997 through the USF Regional Genetics Progr am we evaluated 566 propositi with suspected or clinically diagnosed neurof ibromatosis (NF1, NF2, segmental NF=NF5, NF\Noonan syndrome, familial cafe- au-lait macules, and solitary neurofibroma, NF), These index cases were par t of 32,715 families evaluated during the period. NF1 was the diagnosis in 361; 2 of them had penile NFs. A toddler presented with congenital plexifor m NF of the penile shaft and another propositus developed two small subcuta neous NFs, on the penile shaft and on the left scrotal wall, respectively. A review documented 26 additional patients with penile NF, As to the pathog enesis of the NF1 lesions, a paracrine growth model including the multiple levels of regulation of expression of the NF1 gene appeared more plausible than the loss of heterozygosity (LOH) model, which ignores the complexity o f the paracrine growth mechanism, Am. J. Med. Genet. 87:1-5, 1999, (C) 1999 Wiley-Liss, Inc.