Figure 2: Microscopic examinations of the sublingual BCAC. (A) (B)(C) The tumor was predominantly composed of a proliferation of mildly atypical epithelial cells, often arranged in a cribriform (A, B) or alveolar (C, left) growth pattern with peripheral nuclear palisading (A) and sometimes squamous differentiation (C, right), embedded in a prominent eosinophilic hyaline material (A, inset). On high-power view, these neoplastic cells revealed a small to medium-sized and round shape, having hyperchromatic enlarged nuclei, occasionally conspicuous nucleoli (arrows), and scant cytoplasm (B, C). Mitotic figures were very rarely encountered (H&E stains). Bars = 200 μm (A) and 100 μm (B, C). (D) In addition, these tumor nests showed perineural involvement (arrowheads) (H&E stains) (left). Immunohistochemistry for S-100 protein highlighted it (right). Bar = 100 μm.