We read with interest the vignette by Ingordo et al1 in a recent issue of the Archives. Examining 56 183 young men (aged 17 and 18 years), the authors found 11 cases of neurofibromatosis (NF) type 1 and one case of segmental NF (SNF). In this group, the relative frequency was 0.02% for NF and 0.0018% for SNF.
During the period from November 1988 through August 1995, 308 patients with NF type 1 according to the criteria of the National Institutes of Health consensus conference2 were seen in our NF consultation. During the same period, we saw nine patients with SNF (NF type 5), according to the classification of Riccardi.3 Our nine cases were classified as true SNF according to the criteria of Roth et al.4
As requested by Ingordo et al, we provide more observations to evaluate the frequency of SNF. Despite the recruitment bias