Representative morphologic character of tumor cells according to the new NPC classification. Typical NPC histological appearances. The epithelial carcinoma (EC) subtype shows round cells with prominent nucleoli and a pavement-like appearance, with a low nucleus: cytoplasm ratio (A). The sarcomatoid carcinoma (SC) subtype features irregular small cells and uniform medium-sized spindle cells (B). The mixed sarcomatoid-epithelial carcinoma (MSEC) subtype is characterized by a scattered infiltration of large, round cells in the spindle cell carcinomatous tissue without obvious boundaries (C). The squamous cell carcinoma (SCC) subtype shows well-differentiated keratinizing SCC with a large number of whorls and keratin (D).