HCCs lack portal tracts, Kupffer cells (CD68+), and cohesive connective tissue frameworks. Some eosinophilic tumor cells are surrounded by fibrous bands, which may be difficult to distinguish from large vessel invasion (also common in HCC). Regardless of histologic grade, vascular invasion is an independent poor prognostic factor. In all cytologic patterns of HCC, the tumor cells resemble non-neoplastic hepatocytes with varying degrees of nuclear atypia. The tumor cells tend to retain their polygonal shape, round vesicular nuclei, and prominent nucleoli.