Prediction of the lymphatic, microvascular, and perineural invasion of pancreatic neuroendocrine tumors using preoperative magnetic resonance imaging

Figure 1 A 58-year-old man with pancreatic neuroendocrine tumor grade 2 underwent magnetic resonance imaging. A-C: Magnetic resonance imaging images demonstrated the regular tumor characteristics on T2-weighted imaging (A), diffusion-weighted imaging (B) and arterial phase (C) of contrast enhanced images. The tumor shows ill-defined nodular tumor-pancreas interface with infiltrative to adjacent normal pancreatic parenchyma; D: Hematoxylin-eosin (HE) staining (× 400) reveal that the nerve (black arrowhead) is invaded by the tumor (black arrow); E: HE staining (× 400) shows that the tumor (black arrow) is located in the vascular lumen.