PMC10162764_01
Clinical image showing a solitary, ill-defined, pigmented plaque measuring 4 x 3 cm with an irregular surface over the left malar area extending to the left temporal area along with multiple, discrete pigmented papules on the left cheek
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F1
On examination, a solitary, ill-defined, pigmented plaque measuring 4 x 3 cm with an irregular surface was present on the left malar area extending to the left temporal area along with multiple, discrete pigmented papules on the left cheek [Figure 1].
Histopathological image in scanner view (10x) showing coarse hyalinized collagen deposition throughout the dermis replacing the subcutaneous fat as well
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F2
On histopathological examination, sections from both specimens showed normal looking epidermis with collagen proliferation throughout the dermis, replacing the subcutaneous fat [Figure 2] with perifollicular fibrosis and atrophy [Figure 3], more indicative of a collagenoma.
Histopathological image in high power view (40x) showing perifollicular fibrosis with atrophy
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F3
On histopathological examination, sections from both specimens showed normal looking epidermis with collagen proliferation throughout the dermis, replacing the subcutaneous fat [Figure 2] with perifollicular fibrosis and atrophy [Figure 3], more indicative of a collagenoma.
(a and b) Section showing negativity for Desmin and CD34, respectively, (c) Section showing a light blue color on Masson's trichrome staining, indicative of collagen. The absence pf black staining shows the negative staining for elastic fibers
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F4
Immunohistochemistry with CD34 and Desmin was done to look for blood vessel proliferation and smooth muscle, respectively, and both were found to be negative. [Figure 4a and b] Special stains with Masson's trichrome stained the slide blue [Figure 4c], confirming the collagen proliferation and a diagnosis of collagenoma.