Ann Dermatol.  2013 May;25(2):226-228. 10.5021/ad.2013.25.2.226.

Two Cases of Vitiligo Developed on the Persisting Dermal Melanocytosis: Is There a Difference between Epidermal Melanocytes and Dermal Melanocytes?

• Ahn JJ
• Lee JH
• Shin MK
• Lee MH

• KMID: 2171794
• DOI: http://doi.org/10.5021/ad.2013.25.2.226

Abstract

Vitiligo is one of the most common pigmentary skin disorders; it is characterized by circumscribed depigmented macules due to the destruction of melanocytes. Although the etiology of vitiligo has not been fully elucidated, multiple factors including autoimmune and oxidative stress have been implicated in the pathogenesis of vitiligo. In contrast, dermal melanocytosis is histologically characterized by the presence of dermal melanocytes. It has been described that there are ectopic dermal melanocytes, which have failed to reach their proper location. A literature search revealed very few reports of patients with vitiligo developing vitiligo within dermal melanocytosis. Here, we report two cases of patients with vitiligo that occurred at pre-existing sites of dermal pigmented lesions. The histopathology showed the loss of epidermal melanocytes in spite of the existence of melanocytes in the dermis. There was no significant infiltration of inflammatory cells in the dermis. These cases illustrate unknown environmental factors as well as heterogeneity.

Keyword

Dermal melanocytosis; Vitiligo

MeSH Terms

Dermis
Humans
Melanocytes
Oxidative Stress
Population Characteristics
Skin
Vitiligo

Figure

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  Fig. 1 Case 1. (A) White patches developed within or around the preexisting bluish pigmented patch. (B) Spindle or dendritic cells containing brownish melanin granules are scattered between dermal collagen bundles (H&E, ×100). (C) The spindle cells were positive for S-100 protein staining and there were no melanocytes present in the basal layer of the epidermis (×100, inset: ×400).

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  Fig. 2 Case 2. (A, B) Extensive white patches developed, ultimately including the preexisting bluish pigmented patches (arrows) on the left scapular area and lower back. (C) Spindle cells containing melanin granules were scattered throughout the dermis (H&E, ×100; inset: ×400). (D) On the S-100 protein immunoperoxidase staining, disappearance of epidermal melanocytes was observed (the right side of the arrow head); however, dermal melanocytes were observed in spite of the vitiliginous epidermal changes (×100; inset: ×400).

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