The gastrointestinal manifestations of the Zollinger-Ellison syndrome are well known, but to our knowledge direct radiologic demonstration of the pancreatic tumor has not been previously described. The case reported here is that of a patient with a clinical diagnosis of Zollinger-Ellison syndrome in whom the diagnosis of isletcell carcinoma was made by selective angiography prior to surgery. Case Report A 55-year-old white man was treated for a peptic ulcer from 1963 until 1965 when a clinical diagnosis of Zollinger-Ellison syndrome was first made on the basis of gastric analysis values typical of this condition. In 1966 the patient's symptoms became refractory to anticholinergic therapy. Radiologic examinations had demonstrated gastric hypersecretion, an ulcer of the duodenal bulb, questionable ulceration of the third part of the duodenum, and prominent mucosal folds in the stomach, duodenum, and proximal jejunum. A few punctate calcifications had been noted in the body of the pancreas. There was no clear evidence of a pancreatic mass on gastrointestinal examination. Selective celiac arteriography revealed a large area of hypervascularity in the body of the pancreas. A dense irregular tumor stain persisted for several seconds (Fig. 1). The dorsal pancreatic and pancreatic magna arteries were the principal source of blood supply to the tumor. Selective superior mesenteric arteriography was normal. The radiologic diagnosis of probable islet-cell carcinoma of the pancreas was based on the large size of the tumor and its high incidence in the Zollinger-Ellison syndrome. At laparotomy a grayish-white tumor measuring 3 × 4 × 8 ern was found, involving the body of the pancreas, with evidence of local invasion but no distant metastases. Total gastrectomy was performed. Biopsy of the tumor revealed a regular trabecular pattern of cells with a rich capillary network (Fig. 2). There was extensive hyalinization of some portions of the tumor, but no calcification was found in the biopsy specimen. Na mitoses were noted, but tumor cells were present in lymphatic channels in the periphery of the lesion. Special stains failed to reveal beta islet cells. The pathologic diagnosis was non-beta islet-cell carcinoma. Discussion The experience which has been gained in the angiographic diagnosis of pancreatic tumors provides the rationale for selective arteriography in the Zollinger-Ellison syndrome. The usual adenocarcinoma of the pancreas is a relatively avascular lesion, and diagnosis has been based primarily on tumor invasion and distortion of existing vessels (1, 5–7, 10, 11). On the other hand, tumor neovascularization or readily recognizable tumor stains have been regular features in the small number of reported cases of beta islet-cell (insulin-producing) tumors (1, 3, 7, 8, 11), cystadenomas (2, 9, 10, 12), and pancreatic sarcomas (7, 11) studied by angiography.