Becker’s nevus is not a nevocellular nevus because it lacks nevus cells. The lesion is a developmental anomaly consisting of either a brown macule, a patch of hair, or both. Nonhairy lesions may later develop hair. The lesions appear in adolescent men on the shoulder, submammary area, and upper and lower back. Becker’s nevus varies in size and may enlarge to cover the entire upper arm or shoulder. The border is irregular and sharply demarcated. Malignancy has never been reported.
Becker nevus syndrome is the presence of an epithelial nevus showing hyperpigmentation, increased hairiness and hamartomatous augmentation of smooth muscle fibers, and other developmental defects such as ipsilateral hypoplasia of breast and skeletal anomalies including scoliosis, spina bifida occulta, or ipsilateral hypoplasia of a limb. The Becker nevus syndrome usually occurs sporadically. Becker’s nevus is usually too large to remove by excision. The hair may be shaved. Laser removal of hair and pigmentation is reported.