PMC9467741_01
An ill-defined hyperpigmented patch with a wrinkled surface.
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fig1
A physical exam revealed a large well-demarcated hyperpigmented thin plaque with a rim of annular erythema extending from the left axilla to the medial upper arm, suggestive of uncertain etiology (Figure 1).
A large, slightly scaling, hyperpigmented patch on the right abdomen.
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fig2
Various subtle hyperpigmented ill-defined patches with a wrinkled appearance were present on the lateral right abdomen (Figure 2).
a-c) Lymphocytes, some larger and atypical, in the interstitial pattern in the dermis (hematoxylin & eosin, 4x, 10x, and 20x magnification).
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fig3
Three punch biopsies were obtained from the axilla and abdomen, all of which revealed an interstitial pattern of cells in the dermis with prominent small aggregates of mildly enlarged atypical lymphocytes and a few histiocytes associated with a mild increase in dermal mucin (Figures 3(a)-3(c) and 4).
Atypical, enlarged interstitial lymphocytes with positive staining for CD8 in the biopsy from the L axilla (CD8 immunostain, 20x magnification).
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fig5
Ancillary immunohistochemistry demonstrated that the atypical lymphocytes in the dermis stained positive for CD3 and CD8 (Figure 5) and negative for CD4 and CD7 (Figure 6), an aberrant immunoprofile.
CD4 staining of lymphocytes is decreased in number in the biopsy from the L axilla when compared to CD8 (CD4 immunostain, 20x magnification).
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fig6
Ancillary immunohistochemistry demonstrated that the atypical lymphocytes in the dermis stained positive for CD3 and CD8 (Figure 5) and negative for CD4 and CD7 (Figure 6), an aberrant immunoprofile.
CD68 staining of dermal histiocytes (CD68 immunostain, 10x magnification).
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fig7
CD20 positive B lymphocytes. CD68 stained a few intermixed dermal histiocytes (Figure 7), and S100 protein stained dermal dendritic cells as well as marked Langerhans cells in the overlying epidermis (Figure 8), producing a pattern mimicking interstitial granuloma annulare.
S100 protein staining dermal dendritic cells and Langerhans cells in the epidermis (S100 protein immunostain, 10x magnification).
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fig8
CD20 positive B lymphocytes. CD68 stained a few intermixed dermal histiocytes (Figure 7), and S100 protein stained dermal dendritic cells as well as marked Langerhans cells in the overlying epidermis (Figure 8), producing a pattern mimicking interstitial granuloma annulare.