Inactive malignant endocrine tumors of the pancreas.

The angiographic pattern of four non-active endocrine tumors is reported. Three of the tumors were highly vascular and had a characteristic angiographic appearance as observed in a few case reports in the literature. One tumor was angiographically avascular with irregularly scattered calcifications. Similar calcifications in a malignant tumor of the pancreas causing the Zollinger-Ellison syndrome are presented. Hypervascular tumor tissue was observed in the periphery of the calcification. The types of calcification and angiographic characteristics are of diagnostic importance in the differential diagnosis between endocrine tumors and other highly vascular tumors of the pancreas.