Fig. 2

Microscopic features of salivary duct carcinoma on hematoxylin and eosin staining. a, b The tumor was composed of a neoplastic component characterized by atypical ductal epithelial cells, a cribriform growth pattern, and comedo-like central necrosis. c The epithelium was primarily composed of polygonal shaped cells with an abundant eosinophilic cytoplasm (numerous mitotic figures) and large nuclei (nuclear atypia). d Lymphatic invasion, e vascular invasion, and f perineural invasion were observed on podoplanin, elastic Van Gieson, and hematoxylin and eosin staining, respectively