Familial Cases of PENS: A Review of the Literature.

Papular epidermal nevus with "skyline" basal cell layer (PENS) is a keratinocytic nevus that can occur sporadically or has a familial transmission. There are 5 families reported with PENS, in which there are 2 family members affected with each case. We present the sixth familial case, with the peculiarity of being the first time in which there are 3 family members with PENS, while reviewing the other cases described until now. In addition, we present a new histopathological finding, an inflammatory lichenoid infiltrate on the upper dermis in PENS lesions. This finding could be the result of trauma to the biopsied lesion, or it may represent a new inflammatory histological variant.