Figure 8. Tumour(T) in the uncinate process of the head of the pancreas tethered the superior mesenteric vein (SMV) (arrow) into a teardrop shape, although the SMV was surrounded by less than 50% of the vessel circumference and vessel wall remained regular. The superior mesenteric artery (SMA) (arrowhead) was also shown to be nearly embedded in tumour. The SMV and the SMA were proven to be infiltrated at surgical exploration.