[Jadassohn's nevus sebaceus and nevus unius lateris. Report of an observation with multiple dysplasia (author's transl)].

The case of a female patient with multiple ectodermal and mesodermal malformations present since birth is reported. The cutaneous lesions were of two types: Jadassohn's nevus sebaceus and nevus unius lateris. These entities have been described in the literature as congenital dermatologic alterations of nevoid character and organoid structure. They can be considered as congenital epidermal nevi. In many cases, including this one, there are various associated disorders especially of the nervous system, eyes, and skeleton. Both syndromes are cutaneous hamartomas which can be differentiated histologically but not by the anomalies accompanying them. Their dermatologic aspects are very similar. The histopathologic characteristics of the skin lesions of nevus unius lateris consist of hyperkeratosis, acanthosis, and epidermal papillomatosis. In Jadassohn's nevus sebaceus there are also alterations of the skin adnexa, namely the absence of hair follicles and the presence of numerous mature sebaceus and hyperplastic glands. In general, the presence of organoid nevus may be a sign of multiple ectodermal and mesodermal malformations. Both syndromes are often present in the same patient, as in the case described here, and their etiology is the same. It is based on an alteration in embryogenic development affecting primarily, though not exclusively, the formations of ectodermal origin. Thus Jadassohn's nevus sebaceus and nevus unius lateris are both forms of phacomatosis. Clinical cases have in common the cutaneous cited above, either in combination or singly. The other possible signs and symptoms are variable, depending on which stage of embryogenic development is affected. There may be defects in the structures of both ectodermal and mesodermal origin.