Segmental neurofibromatosis in association with nevus sebaceus of Jadassohn

We describe an unusual case involving the simultaneous occurrence of segmen tal neurofibromatosis (Type V NF) in a patient with a large nevus sebaceus of Jadassohn in the same physical distribution. Causative mechanisms of dev elopment of these 2 genetic disorders have not been definitively linked. Fa ctors producing these diseases probably involve similar tissues at the same point in development because both have been reported in association with c entral nervous system anomalies and have been classified among the neurocut aneous syndromes. This is a case of a nevus sebaceus occurring in associati on with and in the same physical distribution as segmental NF. These disord ers most likely represent a spectrum of disease within the phakomatoses.