PMC3568418_01
A, Photograph showing the clinical appearance of the lesion. B, Lesion afterincisional biopsy.
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F1
Clinically, the lesions appeared as spots with imprecise borders, had a brown to dark brown color, and presented a tendency towards nodule formation (Figure 1).
Histopathological appearance of melanoacanthoma stained with hematoxylin-eosin at different magnifications (A: 100x; B: 200x; C: 400x) and stained with periodic acid Schiff at 200x magnification (D).
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F2
In view of the histopathological findings, a diagnosis of MA was made (Figure 2).
Immunostainingfor melan-A at three different magnifications.
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F3
Anti-Ki-67, anti-MCM-2 and anti-geminin antibodies only reacted with cells of the basal and suprabasal layers of the epithelium, whereas MCM-5 staining was negative (Figures 3 and 4).
Immunostaining for geminin (A), Ki-67 (B), MCM-2 (C), and MCM-5 (D).
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PMC3568418_01_1756-0500-6-30-4.jpg
F4
Anti-Ki-67, anti-MCM-2 and anti-geminin antibodies only reacted with cells of the basal and suprabasal layers of the epithelium, whereas MCM-5 staining was negative (Figures 3 and 4).