Ewing Sarcoma of the External Ear Canal

Figure 2

(a) Tumor cells are uniform small round cells with round nuclei containing fine chromatin, high nuclear to cytoplasmic ratio, and indistinct cytoplasmic membrane (H&E; 20x). (b) Tumor cells are uniform small round cells with round nuclei containing fine chromatin, high nuclear to cytoplasmic ratio, and indistinct cytoplasmic membrane (H&E; 40x). (c) Immunohistochemical staining for vimentin (40x). (d) Immunohistochemical staining for FLI1 (40x). (e) Immunohistochemical staining for CD99 (40x).

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