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Skin-Melanocytic tumors
Vitiligo
Author: Nat Pernick, M.D., PathologyOutlines.com, Inc.
Revised: 5 July 2009, last major update November 2008
Copyright: (c) 2005-2009, PathologyOutlines.com, Inc.
Definition
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● Partial or complete loss of pigment producing melanocytes within the epidermis
Epidemiology
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● Affects 1% of world’s population; more noticeable in dark skinned individuals
● Usually hands/wrists, axilla, perioral, periorbital, anogenital skin
Clinical
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● An autoimmune disorder associated with pernicious anemia, Addison’s disease, Hashimoto’s thyroiditis
● Perilesional skin up to 5 cm from vitiligo spot is still lighter than normal (Photodermatol Photoimmunol Photomed 2008;24:314)
● Associated with polymorphisms in COX2 gene (J Dermatol Sci 2009;53:176), mutations of autoimmune regulator gene (Br J Dermatol 2008;159:591)
● May cause severe psychological distress
Patterns
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● Focal (only a few areas)
● Segmented (one side of the body only)
● Generalized (most common, both sides of body)
● Trichrome - patient has three shades of skin color
Treatment and prognosis
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● Laser skin ablation
● Phototherapy
● 5 FU (Photodermatol Photoimmunol Photomed 2008;24:322)
● Topical steroids or immunomodulators (J Dermatol 2008;35:503)
● Hydroxyacetone (Dermatol Online J 2008;14(8): 23)
Clinical description
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● Asymptomatic, flat, well-demarcated zones of pigment loss
Clinical images
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Hand Various images
Micro description
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● Difficult to diagnose by micro alone; decreased melanocytes (use S100 or MelanA and control biopsy from adjacent normal skin, Am J Dermatopathol 2008;30:112)
Electron microscopy
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● No melanocytes
Differential diagnosis
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● Albinism - melanocytes present, but no melanin due to defect in tyrosinase enzyme
Additional references
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End of Skin-Melanocytic Tumors > Vitiligo
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