case_images: PMC6458953_01
case_images: The large nodulo-ulcerative plaque with bleeding seen on frontal view; located at the back of the right upper arm, measuring 12 cm x 6 cm.
case_images: CRIDM2019-4503272.001.jpg
case_images: PMC6458953_01_CRIDM2019-4503272.001.jpg
case_images: fig1
case_images: On examination, a large nodulo-ulcerative plaque was noted on the right upper arm, measuring approximately 12 cm x 6 cm in size (Figure 1).
case_images: Axial view of the dermatofibroma (arrowhead) on magnetic resonance imaging; invasion to the deltoid and triceps brachii muscles is seen.
case_images: CRIDM2019-4503272.002.jpg
case_images: PMC6458953_01_CRIDM2019-4503272.002.jpg
case_images: fig2
case_images: Magnetic resonance imaging (MRI) revealed a mass measuring 12 cm x 6 cm x 1.5 cm, invading the deltoid and triceps brachii muscles (Figure 2).
case_images: (a) Proliferation of spindle cells with vague storiform growth pattern and basal cell hyperplasia of overlying epidermal cells noted on hematoxylin and eosin staining. (b-d) Immunohistochemical stain showing positivity for (b) SMA, (c) CD 68, and (d) factor XIIIa.
case_images: CRIDM2019-4503272.003.jpg
case_images: PMC6458953_01_CRIDM2019-4503272.003.jpg
case_images: fig3
case_images: Histopathological examination following hematoxylin and eosin stain revealed spindle cell proliferation with a vague storiform growth pattern and basal cell hyperplasia in the overlying epidermal cells (Figure 3(a)). The tumor tested negative for CD 34 on immunohistochemical staining but tested positive for SMA, CD 68, and factor XIIIa (Figures 3(b)-3(d)).