Figure 1. Typical Morphologic Features of Pancreatic WD-NET, PD-NEC-SCC, and PD-NEC-LCC.
WD-NETs (A-B) revealed nested/organoid and trabecular architecture, a regular intratumoral vascular pattern, abundant granular cytoplasm, and stippled nuclei with inconspicuous nucleoli. PD-NEC-SCC (C-D) demonstrated stromal desmoplasia (C), tumor necrosis (C), fusiform (“oat cell”) nuclei lacking nucleoli, and nuclear molding. PD-NEC-LCC (E-F) displayed tumor necrosis, expansile and irregular nests with peripheral palisading, and rosettes/tubular structures within the large nests.