Figure 19a. Metastatic appendiceal carcinoid tumor with an infiltrative growth pattern in a 26-year-old woman. (a) Axial contrast-enhanced CT scan shows a poorly defined soft-tissue mass with a focus of eccentric calcification located near the root of the mesentery (arrowhead). (b) Axial contrast-enhanced CT scan obtained inferior to a shows diffuse wall thickening of the appendix (arrowhead) from the infiltrating primary appendiceal carcinoid tumor.