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Skin-Melanocytic Tumors
Blue nevus - Common type
Last major update: November 2008 - next update November 2009
Revised: 18 September 2009
Author: Nat Pernick, M.D., PathologyOutlines.com, Inc.
Copyright (c) 2002-2009, PathologyOutlines.com, Inc.
Definition
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● See also Eye-Conjunctiva
● 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)
Epidemiology
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● Associated with neurocutaneous melanosis
● Usually small lesions of head, neck or upper extremity of young adults, particularly women
● Blue color due to the Tyndall effect of selective absorption of parts of the light spectrum by deeply located (dermal) melanin pigment, which is usually abundant
Case reports
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● Plaque-like tumors (AJSP 2000;24:92)
● Subungual tumor (J Am Acad Dermatol 2008;58:1021)
● Poliosis (patch of gray/white hair) overlying a nevus with blue nevus features (Dermatol Online J 2008;14(2):20)
● Persistent tumor (J Am Acad Dermatol 2004;50:S118)
● With satellitosis (J Eur Acad Dermatol Venereol 2001;15:570)
● Multiple blue nevi of penis (J Cutan Pathol 2004;31:185)
● Involvement of nodal capsule #1 (AJCP 1984;81:367), #2 (Pathologica 1992;84:547)
Clinical description
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● Heavily pigmented, solitary, < 1 cm, slightly elevated or dome-shaped
Clinical images
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Various images
Dermoscopy description
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● Homogeneous, structureless pigment pattern with various colors (blue, white-blue, brown, black, polychromatic, J Cutan Pathol 2007;34:543)
● Acral tumors may simulate melanoma (Dermatology 2007;214:174)
Dermoscopy images
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Homogeneous blue-gray pattern with central hypopigmented area
and no pigmented network, dots or globules
Micro description
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● Ill defined deep dermal proliferation of spindled melanocytes with abundant pigment and melanophages, dissecting dermal collagen and often extending into subcutis
● No junctional or superficial dermal involvement
Micro images
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Various images
10x
20x
40x
Contributed by Angel Fernandez-Flores, MD, PhD, Hospital El Bierzo and Clinica Ponferrada, Spain
Positive stains
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● S100, HMB45, MelanA/Mart1, other melanocytic stains; variable CD34
Videos
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Differential Diagnoses
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● Benign fibrous histiocytoma - hemosiderin pigment, no melanin
● Dermatofibrosarcoma protuberans - tight storiform pattern, infiltrative, has pigmented variant
● Metastatic melanoma
Additional references
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End of Skin-Melanocytic Tumors > Blue nevus
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