Becker Nevus

Concern about the large, hairy "mole" on his left shoulder prompted a 24-year-old African American man to seek medical attention. The lesion first appeared during early adolescence as a group of small, dark blotches. These eventually coalesced into a hyperpigmented patch with hair and acne.

Physical examination findings were otherwise normal. The patient had no significant personal or family history of similar lesions, skin disease, or skin cancer.

This is a classic presentation of a Becker nevus--a hyperpigmented, unilateral patch with hypertrichosis that develops during adolescence--writes Kendall Lane, MD, of San Diego. The lesion is fairly uncommon and affects men more than women. Acneform lesions may appear within the nevus, as in this patient. Becker nevi on the lower extremities, head, and hands have been reported.^1-3 The clinical history usually rules out other lesions in the differential diagnosis, which includes congenital melanocytic nevus, nevus spilus, caf au lait patch, and postinflammatory hyperpigmentation.

Abnormalities, such as smooth muscle hamartoma,⁴ cystic lymphangioma,⁵ polythelia,⁶ unilateral breast hypoplasia,⁷ ipsilateral pectoralis major hypoplasia,⁸ asymmetric scalp and beard growth,² ipsilateral limb asymmetry,⁹ lichen planus,¹⁰ and accessory scrotum,¹¹ have been associated with Becker nevi. This patient had none of these conditions.

The co-occurrence of Becker nevi and melanoma has been rarely reported. In a study of 9 patients with Becker nevi and melanoma, the malignancy developed within a Becker nevus in only 1 patient, on the ipsilateral side of the body in 5 patients, and on the contralateral side in 3 patients.¹²

Treatment is usually for cosmesis. Surgical excision is generally avoided because it may result in scarring. In contrast, laser therapy (eg, erbium YAG laser and long-pulsed ruby laser) has been used to treat both hyperpigmentation and hypertrichosis with a good cosmetic outcome.

This patient was on active duty in the Navy and planned to pursue laser treatment after his deployment.

The views expressed herein are those of the author and do not reflect the official policy or position of the Department of the Navy, Department of Defense, or the US government.

References:

REFERENCES:1. Hsu S, Chen JY, Subrt P. Becker's melanosis in a woman. J Am Acad Dermatol. 2001;45:S195-S196.
2.de Almeida HL Jr, Happle R. Two cases of cephalic Becker nevus with asymmetrical growth of beard or scalp hair. Dermatology. 2003;207:337-338.
3.Al Aboud K, Al Hawsawi K. Becker nevus on the hand. Eur J Dermatol. 2002;12:588.
4. Urbanek R, Johnson WC. Smooth muscle hamartoma associated with Becker's nevus. Dermatol. 1978;114:104-106.
5. Oyler RM, Davis DA, Woosley JT. Lymphangioma associated with Becker's nevus: a report of coincident hamartomas in a child. Pediatr Dermatol. 1997;14:376-379.
6. Urbani CE, Betti R. Polythelia within Becker's naevus. Dermatology. 1998;196:251-252.
7.Van Gerwen HJ, Koopman RJ, Steijlen PM, Happle R. Becker's naevus with localized lipoatrophy and ipsilateral breast hypoplasia. Br J Dermatol. 1993;129:213.
8. Moore JA, Schosser RH. Becker's melanosis and hypoplasia of the breast and pectoralis major muscle. Pediatr Dermatol. 1985;3:34-37.
9. Lucky AW, Saruk M, Lerner AB. Becker's nevus associated with limb asymmetry. Arch Dermatol. 1981;117:243.
10. Puri S, Nanda S, Grover C, et al. Congenital Becker nevus with lichen planus. Pediatr Dermatol. 2005;22:328-330.
11. Szylit JA, Grossman ME, Luyando Y, et al. Becker's nevus and an accessory scrotum. A unique occurrence. J Am Acad Dermatol. 1986;14:905-907.
12. Fehr B, Panizzon RG, Schnyder UW. Becker's nevus and malignant melanoma. Dermatologica. 1991;182:77-80.