[Von Recklinghausen neurofibromatosis and dermal melanocytic nevi].

Neurofibromas, café au lait macules and freckles in the axillary or inguinal regions are common manifestations of von Recklinghausen's neurofibromatosis (NF-1). Less known is the simultaneous appearance of dermal melanocytic naevi. We describe the case of a 21-year-old Vietnamese woman who showed generalized, multiple neurofibromas, a solitary plexiform neurofibroma in the left gluteal region and Lisch nodules. In addition, there were several large grey-blue macules histologically characterized by fusiform pigment-bearing cells in the dermis, which we diagnosed as persistent aberrant mongolian spots. In the right zygomatic region she presented a grey-blue, hair-bearing macule, which we saw as a variant of Ota's naevus. A genetic background for this coincidence of a systemic with a local phakomatosis can be supposed, as both Schwann's cells and melanocytes are derived from the neural crest. Such pathologic rearrangement in the embryogenesis of the cellular elements could be important for the pathogenesis of NF-1 and dermal melanocytic nevi.