DISCUSSION
First described by William Becker in 1948 (and subsequently named for him), the Becker nevus (BN) received little research attention until a French study of 20,000 young men showed a prevalence of 0.5%. Nearly half of the subjects had first noticed the lesion before the age of 10—a somewhat surprising finding, since abundant evidence implicates androgens in its genesis. (This is supported by the condition’s predominance in males, the increased numbers of androgen receptors and melanocytes in the affected skin, and the prevalence of hypertrichosis.)
The researchers were also surprised to find that only 30% of the reported lesions occurred above the nipple, because the first descriptions of BN gave the impression that the shoulder and chest were most commonly affected. We now know that BN can also be found on arms and legs.
Usually a benign condition, BN can be associated with skeletal or soft-tissue deformities in the affected area (eg, ipsilateral breast hypoplasia). Malignancies—most notably melanoma—have also been reported with BN but are especially uncommon.
The differential includes the café-au-lait macules of neurofibromatosis, Albright disease, and congenital melanocytic nevus. The history of BN (ie, presentation, hypertrichosis, gender of patient, and distribution) usually allow a clinical diagnosis.
Treatment is limited to laser hair removal or laser removal or reduction of pigment.
TAKE-HOME LEARNING POINTS
- Becker nevus (BN) is far more common in males than females.
- BN typically manifests during puberty, which aligns with the suspected androgenic etiology.
- Though the shoulders and chest are the most commonly affected areas, BNs can also appear on the flank, arms, or legs.
- The lesions are rarely associated with serious pathology; hypoplasia of the ipsilateral breast is the most common of these complications.