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.

Figure 2 A 52-year-old woman with pancreatic neuroendocrine tumor grade 1 underwent magnetic resonance imaging. A-C: Magnetic resonance imaging (MRI) images revealed the regular tumor characteristics on T2-weighted imaging (A), diffusion-weighted imaging (B) and arterial phase (C) of contrast enhanced images. A round, well demarcated tumor with smooth contours is shown on MRIs (white arrow). The tumor pancreas interface is clear; D and E: Hematoxylin-eosin staining (× 400) reveal that the space between the vascular and nerve (black arrow) and the tumor (black arrow) is clear.

Figure 3 The receiver operating characteristic curve for diagnostic performance of multivariate model regarding the lymphatic, microvascular, and perineural invasion of pancreatic neuroendocrine tumors. The area under the curve is 0.855 (95% confidence interval: 0.750-0.960).