One person, two bilateral symmetrical giant Becker nevi

A case of multiple, bilateral Becker’s Nevi of the trunk and lower extremities in a young girl: A case report

“…In a review of the literature, Antunes-Duarte et al identified only 26 cases with multiple or bilateral BN. 1 Eleven of these had multiple bilateral BN in an asymmetric distribution, similar to our case, and only one of these patients had a congenital presentation. The genetic basis of BN was recently elucidated and found to be caused by mutations in the ACTB gene which encodes for beta-actin, a protein responsible for cell migration, proliferation, signaling, and gene expression, and may play a role in the Hedgehog pathway.…”

“…However, clinicians should be aware of syndromic associations, including ipsilateral breast hypoplasia (most common), subcutaneous fat hypoplasia, supernumerary nipples, absent or underdeveloped ipsilateral shoulder girdle musculature, scoliosis, thoracic skeletal anomalies, dental dysplasia, cardiomyopathy, and developmental delay. 1 , 4 , 7 Although considered benign, there are rare reports of tumors occurring within BN, including basal cell carcinoma and desmoid tumor. 8 , 9 BN treatment is optional and dictated by symptoms or cosmetic concerns.…”

“…Whereas, when the ACTB mutations arise later in post-zygotic development, they will give rise to an isolated BN or nevi. 1,7 BN is likely only seen in the mosaic form as a sporadic mutation, as it is thought to be lethal in utero when present in the zygote. 4 Pathologic ACTB variants are also implicated in Baraitser-Winter syndrome, juvenileonset dystonia, and neutrophil dysfunction.…”

“…Becker’s nevus (BN) is a cutaneous hamartoma, occurring in approximately 0.5% of the population. 1 It typically presents as a single unilateral, well-demarcated, hyperpigmented patch that usually presents on the trunk. 1 , 2 Affected skin has increased androgen receptor density and sensitivity and becomes more prominent following puberty due to development of hypertrichosis and increased pigmentation.…”

“… 1 It typically presents as a single unilateral, well-demarcated, hyperpigmented patch that usually presents on the trunk. 1 , 2 Affected skin has increased androgen receptor density and sensitivity and becomes more prominent following puberty due to development of hypertrichosis and increased pigmentation. 3 Consequently, the majority of BN lesions are reported during adolescence and may go unnoticed prior to puberty.…”