Linear nevus sebaceous syndrome: case reports and review of the literature.

Linear nevus sebaceous syndrome is reported to occur in as many as 1 in 1000 live births, and is hypothesized to result from genetic mosaicism involving a lethal autosomal-dominant gene. The terms "epidermal nevus syndrome" and "linear nevus sebaceous syndrome" are often used interchangeably, although linear nevus sebaceous syndrome more strictly applies to patients with a typical midline nevus, and epidermal nevus syndrome is a more inclusive term that includes all varieties of epidermal nevi. Linear nevus sebaceous syndrome encompasses a broad spectrum of abnormalities that may affect every organ system, including the central nervous system. In these cases, seizures and mental retardation are the main manifestations. Many other organ systems were also reported to be involved in this syndrome, including the cardiovascular, skeletal, ophthalmologic, and urogenital systems, among others. Although linear nevus sebaceous syndrome occurs at a relatively high frequency and may affect different organ systems, many physicians are unaware of the syndrome, which may delay diagnosis and treatment. We present two cases of linear nevus sebaceous syndrome, and we describe their initial presentation and subsequent evolution, incorporating a review of the current literature in this field.