A: Photomicrograph of an H & E–stained section, original magnification ×100, showing a combination of solid and papillary architectures, with perivascular rosette formation. An area of necrosis is present. B: Photomicrograph of an H & E–stained section, original magnification ×100, showing a solid tumor area with slightly vacuolated cytoplasm and multiple mitoses (black arrows). C: Photomicrograph of an immunoperoxidase-stained section, original magnification × 64, showing strong immunoreactivity for cytokeratin 8 (clone CAM5.2). D: Photomicrograph of an immunoperoxidase-stained section, original magnification × 100, showing strong immunoreactivity for S100.