Skin-melanocytic tumor
Becker's nevus (Becker's melanosis)

Author: Christopher Hale, M.D. (see Authors page)

Revised: 31 January 2017, last major update March 2013

Copyright: (c) 2003-2017,, Inc.

PubMed Search: becker's melanosis
Cite this page: Becker's nevus (Becker's melanosis). website. Accessed June 20th, 2018.
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)
  • 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)
  • 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:
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Becker Nevus

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Becker's Nevus right shoulder region

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Bilateral Becker’s nevus

Case reports
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