Cerebriform intradermal nevus. A cause of cutis verticis gyrata.

639 Rev Assoc Med Bras 2010; 56(6): 639-41 Cutis verticis gyrata (CVG) is a rare disease that is characterized by excess scalp skin, producing thick folds that form creases and ridges similar in appearance to the whorls of the cerebral cortex. It was first described in the literature by Robert in 1843 and the name cutis verticis gyrata was proposed by Unna in 1907 and remains the accepted name to date. 1,2 It has an estimated prevalence of one case in every 100,000 men and 0,026 cases for every 100,000 women. 3 It can be an isolated manifestation that is present from birth or it can be part of other syndromes. Cutis verticis gyrata is classified as primary (subdivided into essential and non essential) or secondary. The essential primary form is not associated with neurological or ophthalmological disorders, and only the folds on the scalp mimicking the cerebral whorls appear. It appears in puberty and affects more men than women. The non essential primary form affects 0.5% of patients with mental retardation. Cerebral palsy, epilepsy, cataracts and blindness may also be present. 2,4,5,6 The secondary forms of CVG generally occur as a result of inflammatory or neoplastic processes that cause changes to the structure of the scalp. 2,6 One of the rarest forms of secondary CVG is the nevoid form, in which it is melanocytic intradermal nevi that cause the cutaneous hypertrophy. This condition is known as cerebriform intradermal nevus (CIN) and was first linked with CVG in 1937 by Hammond and Ransom. 7 Patients affected by CIN have normal intelligence and are free from other local or systemic diseases. The objective of this paper is to describe a rare case of cerebriform intradermal nevus, discussing its histopathological and clinical features.