Becker nevus presents most commonly as a patchy hyperpigmentation with dark hairs on the upper arms or the shoulder girdle of male patients. Its prevalence has been determined at 0.52 percent in a large cohort of male French military recruits between the ages of 17 and 26 years.1 The male to female ratio of Becker nevus has been approximated to be about 4:1, although it may well be underdiagnosed in women owing to less intense pigmentation and milder or even absent hypertrichosis. An association with soft-tissue defects is common, manifesting most frequently as breast hypoplasia. Danarti et al2 defined a Becker nevus syndrome as the coincidence of Becker nevus and ipsilateral breast hypoplasia, scoliosis, spina bifida, or ipsilateral limb hypoplasia. Becker nevi of the lower extremity are exceedingly rare.
We report the case of a 31-year-old woman from the United Arab Emirates who presented with a lesion that had been present since birth but darkened during adolescence. Following a cesarean section 1 year before presentation, she observed a reduction in girth of the left leg. She also complained of pain on exercise. Examination showed hyperpigmentation and lipoatrophy involving the entire left lower extremity, extending from the left lumbar region to the ankle (Figure). The lesion’s margins were irregular with satellite macules, reminiscent of an archipelago. The circumferences of the left and right thighs were 56 and 68 cm, respectively. There was only minimal hypertrichosis, and that was restricted to the ventral aspect of the left thigh. The patient underwent 7.5-MHz sonography, which revealed thinning of the subcutis of the left side (1.04 cm) compared with the right side (2.57 cm). Histopathologic analysis showed increased melanin production with pronounced pigmentation of the basal cell layer.
Front (A) and posterior (B) views.
The patient desired to improve the cosmetic appearance of the affected leg, which required extensive plastic surgery. This, again, was declined by the patient, and she was lost to follow-up for 3 years.
Khaitan et al,3 in 1998, were the first to describe a patient with Becker nevus of the lower limb. Subsequently, 11 more cases of Becker nevus of the leg have been reported.4 In 2 patients, the reports explicitly noted the absence of hypertrichosis. In 2 female patients, Becker nevus was associated with localized lipoatrophy: a 14-year-old girl with a soft-tissue defect on the ventral aspect of her thigh and a 45-year-old woman with lipoatrophy on the right thigh.5 The case presented herein is unusual because the Becker nevus extended below the knee and involved almost the entire leg.
Corresponding Author: Thomas Herzinger, MD, Klinik und Poliklinik für Dermatologie und Allergologie, Ludwig-Maximilians-University, Frauenlobstr. 9-11, 80337 Munich, Germany (Thomas.Herzinger@med.uni-muenchen.de).
Published Online: July 10, 2013. doi:10.1001/jamadermatol.2013.4736
Conflict of Interest Disclosures: None reported.
Additional Contributions: We are indebted to Diana Kellermeier and Carla Lingner for clinical photography.
Gauglitz G, Müller DS, Molin S, Ruzicka T, Herzinger T. Becker Nevus of the Leg With Lipoatrophy. JAMA Dermatol. 2013;149(9):1115-1116. doi:10.1001/jamadermatol.2013.4736