Case 2 histopathology showing dense atypical infiltrate composed of medium-size cells with irregular nuclear contours, fine chromatin, and scant cytoplasm, resembling undifferentiated blast cells with frequent mitoses and scattered admixed foamy macrophages, some with hemosiderin diffusely involving the dermis. (A) Hematoxylin and eosin stain (2×); (B) hematoxylin and eosin stain (40×).