Skin-melanocytic tumor
Nevi
Blue nevus - common type

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

Revised: 31 January 2017, last major update September 2014

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

PubMed Search: blue nevus [title] common type
Cite this page: Blue nevus - common type. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/skintumormelanocyticBluenevus.html. Accessed April 28th, 2017.
Definition / general
  • Collection of benign type C melanocytes (Schwann cell-like morphology) in dermis (eMedicine)
  • Blue color due to Tyndall effect of selective absorption of parts of the light spectrum by deeply located (dermal) melanin pigment, which is usually abundant
  • No relationship to blue rubber bleb nevus syndrome (eMedicine)
  • May be due to arrested migration of immature melanocytes in dermis
  • May evolve from ordinary non-blue nevi (Ann Diagn Pathol 2007;11:160)
  • Numerous histologic variants and related entities; see also blue nevus variants and eye-conjunctiva
Epidemiology
  • Associated with neurocutaneous melanosis
  • Young adults, particularly women
Sites
  • Usually small lesions of head, neck or upper extremity
Clinical features
  • Heavily pigmented, solitary, < 1 cm, slightly elevated or dome-shaped
Case reports
Dermoscopy
Microscopic (histologic) description
  • Ill defined deep dermal proliferation of spindled (Type C) melanocytes with abundant pigment and melanophages, dissecting dermal collagen and often extending into subcutis
  • No junctional or superficial dermal involvement
Microscopic (histologic) images

Images hosted on Pathout server:
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Contributed by Angel Fernandez-Flores, MD, PhD, Hospital El Bierzo and Clinica Ponferrada, Spain

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Blue nevus (breast skin), courtesy of Dr. Mark R. Wick



Images hosted on Flickr:
Contributed by John Irlam, DO:

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Images hosted on other servers:
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Various images

Positive stains
  • S100, HMB45, MelanA / Mart1 (Arch Pathol Lab Med 2011;135:853) and other melanocytic stains; variable CD34
  • HMB45 staining is usually diffuse; maturational pattern of staining seen in other nevi often not present
Molecular / cytogenetics description
Differential diagnosis