Bifocal type 2 segmental neurofibromatosis.

Abstract

As in other autosomal dominant diseases, even in NF1 segmental lesions can be present (1, 2, 3, 4). The latter can arise on normal skin (type 1 segmental NF1) or in the context of generalized NF1 (type 2 segmental NF1). In the latter event the segmental lesions are severer and earlier than in the rest of the skin.
Type 1 segmental NF1 is due to a post-zygotic mutation arising in a normal subject. On the other hand, type 2 segmental NF1 is due to a post-zygotic mutation arising in a subject with NF1, with consequent loss of heterozygosity and homozygosis in the affected segment.
In the case here reported we are facing NF1 with type 2 segmental lesions affecting two -left mandibular and right gluteal- segments.