Neurofibromatosi segmentaria. Descrizione di due casi e revisione della letteratura

Two cases of segmental neurofibromatosis (SNF) in a 57-year old woman and in a 52-year old man are reported. Both patients presented linear, exophytic, cutaneous lesions located on the left lumbar and left pectoral regions respectively, dating from 15-20 years. The family history was negative for skin and neurological diseases. Examination revealed multiple, firm, smooth surfaced, skin-colored papules arranged in a linear fashion. Café-au-lait macules, axillary freckling and Lisch nodules were absent. Two papules were surgically excised. Histopathological evaluation showed the features of not encapsulated neurofibromas. In both patients, neurological and ophthalmological investigations were within normal limits. Segmental neurofibromatosis is a rare disorder characterized by the presence of cutaneous neurofibromas with or without café-au-lait macules arranged in linear fashion along one or several dermatomes. This disorder accounts for about 10% of cases of neurofibromatosis. In 93% of cases the patients with SNF have a negative family history of neurofibromatosis, in keeping with the pathogenesis of it (somatic mutation). The incidence of malignant transformation is less then 5% and it seems related with the inactivation of NF1 gene. It is mandatory for the patients with SNF to have an accurate information about their disease as well as a life period of follow-up.