A 20-year-old man presents with a large hyperpigmented patch with increased hair growth on his left upper chest and proximal shoulder girdle. The patient reports that the lesion has slowly increased in size over the past few years but has remained asymptomatic. The patient first noticed a darkened area when he was in high school and now has become self-conscious about its appearance. He notes that he was not born with any unusual markings over this area and is not aware of any previous medical problems. He denies radiation or chemical exposure, excessive sun exposure, or family history of skin cancer.
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Becker nevus, also known as Becker melanosis, is a benign congenital epidermal nevus that has a notable distribution and onset of presentation. The characteristic hyperpigmentation and hypertrichosis of Becker nevus are usually distributed over 1 shoulder and/or upper trunk with presentation occurring after puberty.1,2
Although congenital melanocytic nevus and Becker nevus are characterized by hypertrichosis and hyperpigmentation, the age of presentation helps distinguish the 2 conditions. The common congenital melanocytic nevus appears at birth rather than after puberty. Café au lait spots differ from Becker nevus because of the lack of hair growth with the mole. Although nevus of Ito can occur in the same distribution as Becker nevus and appear during adolescence, nevus of Ito is differentiated from Becker nevus by its distinct blue or gray discoloration.1
There is currently no effective treatment for Becker nevus. Patients should be warned to minimize sun exposure; cosmetic treatment with hair removal and pigment laser therapy may be offered.3,4
Conor Vickers, BSE, is a medical student at the Lewis Katz School of Medicine at Temple University in Philadelphia. Rodrigo Valdes-Rodriguez, MD, is a third-year dermatology resident at Temple University Hospital in Philadelphia.
1. Marks JG, Miller JJ. Lookingbill and Marks’ Principles of Dermatology. 5th ed. New York, NY: Elsevier Saunders; 2013.
2. Danarti R, Konig A, Salhi A, Bittar M, Happle R. Becker’s nevus syndrome revisited. J Am Acad Dermatol. 2004;51(6):965-969.
3. Alegre-Sanchez A, Jiménez-Gómez N, Moreno-Arrones ÓM, et al. Treatment of flat and elevated pigmented disorders with a 755-nm alexandrite picosecond laser: clinical and histological evaluation. Lasers Med Sci. 2018;33(8):1827-1831.
4. Wulkan AJ, McGraw T, Taylor M. Successful treatment of Becker’s nevus with long-pulsed 1064-nm Nd:YAG and 755-nm alexandrite laser and review of the literature. J Cosmet Laser Ther. 2018;20(4):211-214.