Asymmetrical growth of beard due to Becker's nevus on the face: a rare presentation
Editor Becker's nevus otherwise known as Becker's pigmented hairy nevus, is a hamartoma with brown hyperpigmentation and hypertrichosis. The lesions mostly occur in the second and third decades of life and are six times more common in males than in females. Although the lesions may have various shapes, they consistently have a geographic or block like configuration in an irregular fashion; a linear pattern has rarely been reported. The lesions are most frequently localized on the upper half of the trunk and proximal upper extremities. There have been rare case reports of Becker nevus localized on lower extremities. Becker nevus localized on the face has been reported much more rarely in the literature. A 21 year old boy presented with an asymptomatic slight hyperpigmented patch with hypertrichosis localized on his left cheek. The hyperpigmented lesion first developed when he was 14 years old. During puberty, hair developed on the hyperpigmented patch. The patient also complained of having more beard than the other side of his face. Dermatological examination showed a slight hyperpigmented patch (6 7 cm) with hypertrichosis localized on the left cheek. The beard on the opposite of the cheek was less pronounced when compared with the left side (Fig. 1a,b) Physical examination did not reveal any neurologic or musculoskeletal defect. The laboratory tests, including serum androgen level, were normal. The histopathological examination of the biopsy from the hyperpigmented patch revealed mild epidermal acanthosis and hyperpigmentation of the basal layer of epidermis (Fig. 2) There was no underlying smooth muscle proliferation. These findings were consistent with Becker's nevus. Becker's nevus, a cutaneous hamartoma, has been long described along with cutaneous and structural abnormalities. Normally, Becker's nevus appears as single lesion, but multiple lesions have been reported. The lesions commonly have a unilateral distribution on the shoulder, the submammary area and the back, but they also have been described on the forehead, cheek, eyelids, neck, abdomen, hips, lower legs and buttocks. de Almeida and Happle reported two cases of cephalic Becker nevus with asymmetrical hair growth. The last case about Becker nevus localized on face reported by Petraud et al. and it is the eight in the literature. We think it would be interesting to report this case for its rare clinical manifestation.
Journal of the European Academy of Dermatology and Venereology JEADV