Skin nonmelanocytic tumor
Cutaneous muscle tumors & hamartomas
Becker's nevus
Author: Christopher S. Hale, M.D.
Last author update: 1 March 2013
Last staff update: 6 March 2025 (update in progress)
Copyright: 2003-2025, PathologyOutlines.com, Inc.
PubMed Search: becker's melanosis
Table of Contents
Definition / general | Terminology | Epidemiology | Sites | Clinical features | Clinical images | Case reports | Treatment | Microscopic (histologic) description | Differential diagnosisCite this page: Hale C. Becker's nevus. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skintumormelanocyticbeckersnevus.html. Accessed March 31st, 2025.
Definition / general
- Sharply demarcated pigmented macule, often with localized hypertrichosis (eMedicine)
- Dermoscopy: network, focal hypopigmentation, skin furrow hypopigmentation, hair follicles, perifollicular hypopigmentation and vessels (Dermatology 2006;212:354)
Terminology
- Also called pigmented hairy epidermal nevus, Becker's melanosis
- Becker's nevus syndrome: Becker's nevus with congenital abnormalities (J Am Acad Dermatol 2004;51:965)
Epidemiology
- First described by Becker in 1948 (Arch Dermatol 1948;60:155)
- Present in 0.5% of young men (Ann Dermatol Venereol 1981;108:41)
- Sex ratio close to 1:1 despite apparent increase in women due to association with breast hypoplasia (An Bras Dermatol 2010;85:379)
- Associated with high localized androgen receptor expression (J Am Acad Dermatol 1984;10:235, J Am Acad Dermatol 2008;59:834)
- May be associated with hypoplasia of ipsilateral breast (Arch Iran Med 2006;9:68), aplasia of ipsilateral pectoralis major muscle, limb shortening, lipoatrophy (Clin Exp Dermatol 2002;27:27), spina bifida and scoliosis
- Occasionally associated with melanoma, but overall no known increased risk (Dermatologica 1991;182:77)
- Possible association with Kabuki Syndrome (Dermatol Online J 2011;17:1)
Sites
- Usually back, shoulder or chest
Clinical features
- Sharply demarcated, unilateral, hyperpigmented tan macule on back, shoulder or chest
- Hypertrichosis in 50%
Clinical images
Images hosted on other servers:
Bilateral Becker's nevus
Case reports
- 12 year old girl with coexisting segmental nevus depigmentosus (Australas J Dermatol 2007;48:224)
- 18 year old man with bilateral nevus (Indian J Dermatol Venereol Leprol 2008;74:73)
- 24 year old man with hypopigmented pityriasis versicolor developing on pre-existing Becker's nevus (Indian J Dermatol Venereol Leprol 2002;68:43)
Treatment
- Laser (Br J Dermatol 2005;152:308)
- Spironoactone may improve associated breast hypoplasia (J Dermatol 2003;30:154)
Microscopic (histologic) description
- Increased basal layer pigmentation, mild acanthosis, hyperkeratosis and regular elongation of rete ridges
- Variable hypertrichosis
- Areas associated with smooth muscle hamartoma have more pronounced smooth muscle bundles irregularly dispersed within the dermis and unrelated to either hair follicles or vascular channels
- Does not actually contain nevus cells
Differential diagnosis
- Congenital smooth muscle hamartoma
