Fig. 14

GIST. Unenhanced abdominal CT (a) shows a heterogeneous soft-tissue lesion with punctiform calcifications on the horizontal portion of the duodenum (arrow). Abdominal CT after iv contrast (b) shows peripheral enhancement and central necrosis (arrows). Coronal reformation of the same patient (c) better depicts the origin of the lesion (arrow) from the duodenal wall and the endophytic component. Histopathological study revealed a duodenal malignant GIST with pancreatic invasion, central necrosis, and small calcifications. Abdominal CT (d) of another large malignant GIST with exophytic growth pattern (arrowhead), which also shows several other small enhancing parietal metastases, in D2 (arrows)