CASE 141
History: A 41-year-old man presents with dyspepsia and diarrhea.
1. What should be included in the differential diagnosis of the imaging finding shown in Figure A? (Choose all that apply.)
E. Zollinger-Ellison syndrome (ZES)
2. What is the most common location of extrapancreatic gastrinomas?
A. Para-aortic retroperitoneum
3. Besides multiple ulcers, what is another common presentation of gastrinomas?
4. Which of the following statements regarding gastrinomas is true?
D. Endoscopy with ultrasound is an optimal means to assess the duodenal site after resection.
ANSWERS
CASE 141
Zollinger-Ellison Syndrome
1. A, C, D, and E
2. C
3. D
4. B
References
Thompson WM, Norton G, Kelvin FM, et al: Unusual manifestations of peptic ulcer disease. Radiographics. 1981;1:1–16.
Cross-Reference
Gastrointestinal Imaging: THE REQUISITES, 3rd ed, p 98.
Comment
ZES is caused by gastrin secretion from non–islet cell tumors of the pancreas, so-called gastrinomas (see figures). Most (>75%) occur in the pancreas, but this tumor is also known to occur in ectopic locations. Approximately 15% of gastrinomas are found in the duodenum, and the remainder are in the para-aortic region, bladder, ovaries, and liver. About one fourth are associated with multiple endocrine neoplasia type I (MEN-I) syndrome, which also causes tumors of the parathyroid, pituitary, and adrenal glands. Most (approximately 60%) gastrinomas are malignant and have a propensity for early metastasis. The tumors associated with tumors of the parathyroid, pituitary, and adrenal gland in MEN-I syndrome have a smaller incidence of malignancy, however.
On CT, gastrinomas are usually hypervascular and are best seen on the arterial phase of scanning. The small enhancing mass is seen in the pancreatic head just to the right of the origin of the superior mesenteric artery on the coronal CT image in this case (see figures).
Clinically, patients develop peptic ulcer disease because of the acid hypersecretion related to the elevated gastrin levels. Most ulcers in patients with ZES occur in the gastric antrum and duodenal bulb. Occasionally, ulcers occur in the distal duodenum. Although they are uncommon even in patients with ZES, distal duodenal ulcers are so rare in healthy patients that they are considered a feature of the disease. Serum gastrin levels can be variable in patients with ZES, although any level greater than 1000 pg/mL is indicative of the condition. Often a provocative test using secretin is necessary to determine the presence of a gastrinoma. (This test produces a dramatic increase in serum gastrin levels in affected patients.)
Gastric acid hypersecretion may manifest as increased fluid in the stomach, along with thickened rugal folds (see figures). Many patients with gastrinoma also complain of diarrhea. The increased acidity in the small bowel interferes with the function of the small bowel enzymes, resulting in diminished intestinal absorption. In severe cases, a spruelike condition may ensue, with villous atrophy, malabsorption, and steatorrhea.
