Figure 4a.  (a) High-power photomicrograph (original magnification, x1,000; hematoxylin-eosin stain) shows a dense aggregate of small, uniform cells with poorly defined borders, inconspicuous cytoplasm, and round to oval nuclei. (b) High-power photomicrograph (original magnification, x1,000; immunoperoxidase stain) shows numerous cells with strong MIC2 immunoreactivity. The stain is localized mostly in the cell membranes.