PMC5742511_01
A well-demarcated nodule is seen in the dermis (original magnification: x40).
CRIOT2017-8289710.001.jpg
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fig1
Microscopic examination showed a roundish, well-demarcated nodular tumor invading the mid- and deep-dermis, sparing the underlying ear cartilage (Figures 1 and 2).
The dermal tumor spares the underlying ear cartilage (original magnification: x40).
CRIOT2017-8289710.002.jpg
PMC5742511_01_CRIOT2017-8289710.002.jpg
fig2
Microscopic examination showed a roundish, well-demarcated nodular tumor invading the mid- and deep-dermis, sparing the underlying ear cartilage (Figures 1 and 2).
At higher magnification, the tumor consists of spindle cells with eosinophilic cytoplasm and blunt nuclei, forming fascicles surrounding the vessels with thick muscular walls (hematoxylin-eosin-saffron stain, original magnification: x250).
CRIOT2017-8289710.003.jpg
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fig3
Several vascular channels were seen within the nodule, and at the periphery of the lesion, several small round vessels with a thick smooth-muscle wall were present, often merging with the main spindle-cell population of the nodule (Figure 3).
By immunohistochemistry, tumor cells express caldesmon (immunoperoxidase revealed with aminoethylcarbazole) (original magnification: x250).
CRIOT2017-8289710.004.jpg
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fig4
The immunohistochemical study showed that the tumor cells expressed smooth-muscle markers, that is, caldesmon (Figure 4), desmin, and smooth-muscle actin, but not keratin.