A, The spindle tumor cells were arranged in bundles and whirling patterns. B, The scattered lymphocytes (arrows) could be seen in the background of spindle cells. C, The spindle cells had no marked cellular atypia, with pale to eosinophilic cytoplasm, fine chromatin and inconspicuous nucleoli. D, Papillary area showed the surface cuboidal cells and polygonal cells in the stroma. E, Sclerotic area was characterized by hyalinized collagen with scarcely distributed polygonal cells and adenoidal structures consisting of cuboidal cells. F, An adenoidal structure covered with cuboidal cells could be seen in spindle cells area. G, H, The border of the tumor (arrows) was relatively well circumscribed.