Becker's nevus associated with chromosomal mosaicism and congenital adrenal hyperplasia

Polythelia within Becker’s Naevus

“…Becker’s naevus occurs in association with underlying developmental and structural abnormalities of bone and soft tissue [7, 8, 9, 10, 11] as well as with accessory scrotum [12] and congenital adrenal hyperplasia [13]. Various conditions may also develop within Becker’s naevus including smooth muscle hamartoma [14], connective tissue naevus [15], solitary plexiform neurofibroma [16], acneiform papules [17], perforating granulomatous folliculitis [18] and pityriasis versicolor [19].…”

Becker's nevus syndrome revisited

“…Interestingly, mosaicism for a chromosomal abnormality has been documented in fibroblasts derived from a Becker's nevus in one sporadic case. 38 In fact, Becker's nevus seems to fulfill all of the criteria expected from paradominant traits. 62 The disorder would only become manifest when a postzygotic mutation occurred in the developing embryo.…”

“…They include scoliosis 3,8,9,12,23,32,33 ; vertebral defects such as hemivertebrae, cleft vertebrae, or spina bifida occulta 10,15,21 ; fused or accessory cervical ribs 33 ; pectus excavatum 34,35 ; pectus carinatum 10 ; asymmetry of scapulae 23 ; short limb or other forms of limb asymmetry 5,10,13,14,25,34-37 ; bilateral internal tibial torsion 13 ; ipsilateral hypoplasia of the shoulder girdle including absence of the pectoralis major muscle 13,38 ; hypoplasia of sternocleidomastoideus muscle 22 ; or umbilical hernia. 13 …”

The group of epidermal nevus syndromes

“…170 Additional cutaneous abnormalities include patchy hypoplasia of fatty subcutaneous tissue, 171,172 hypoplasia of labium minus, 171 accessory scrotum, 173 and decreased hairiness of the ipsilateral axilla. 174 Musculoskeletal defects include scoliosis, 167,175 vertebral anomalies, 174,176 limb asymmetry, 166,177-180 fused or accessory ribs, 181 pectus excavatum, 178 pectus carinatum, 174 muscular hypoplasia of the shoulder girdle, 182,183 and facial asymmetry with segmental odontomaxillary hypoplasia 184 or dysplasia. 185 Interestingly, Becker nevus syndrome appears to play a role in maxillofacial surgery, because in patients with hemimaxillofacial dysplasia, some authors have mentioned ''hypertrichosis,'' ''hairy nevus,'' or Becker nevus.…”