Pancreatic Neuroendocrine Tumors (Islet Cell Tumors) Treatment (PDQ®): Treatment - Health Professional Information [NCI] - General Information About Pancreatic Neuroendocrine Tumors (Islet Cell Tumors)
The approach to management depends on carefully performed preoperative localization studies and the findings at exploratory laparotomy. In a retrospective case series of 30 patients with 32 pancreatic insulinomas, the combination of preoperative dual-phase thin-section multidetector CT and endoscopic sonography correctly identified and localized all of the tumors. These tests, with or without MRI, have replaced older, more invasive, and technically challenging tests, such as percutaneous transhepatic portal venous sampling and arterial stimulation with venous sampling except for unusual circumstances in which the imaging tests are unsuccessful.[4,9]
Glucagonoma is the third most common endocrine-secreting islet cell tumor. About 75% of glucagonomas are malignant. Necrolytic migratory erythema, hyperglycemia, and venous thrombosis comprise a virtually diagnostic triad. A serum glucagon level greater than 1000 pg/mL confirms the diagnosis. These tumors tend to be large and easily visible on CT scan. Somatostatin receptor scintigraphy scanning may be a useful adjunct in detecting metastases.
Miscellaneous Islet Cell Tumors
These tumors are rare but have defined clinical syndromes associated with specific production of polypeptide hormone production by islet cell tumors. Because of their rarity and similar approaches to management, they are grouped in the section on treatment. Miscellaneous tumors include the following:
- VIPoma (Verner-Morrison Syndrome) is characterized by watery diarrhea, hypokalemia, and achlorhydria.
A serum vasoactive intestinal peptide (VIP) greater than 200 pg/mL is diagnostic. These tumors can generally be easily localized by CT scan. Somatostatin receptor scintigraphy scanning may be a useful adjunct in detecting metastases.
These tumors are particularly rare. They often present with diarrhea, steatorrhea, diabetes, and/or gallstones. Decreased pancreatic secretion of enzymes and bicarbonate accounts for the diarrhea and steatorrhea. Somatostatin-mediated inhibition of cholecystokinin leads to gallstone formation. Somatostatin also inhibits insulin, producing hyperglycemia. The diagnosis is made by a fasting serum somatostatin level greater than 100 pg/mL. CT scan, MRI, and endoscopic ultrasound can usually help localize and stage the tumor. Most of these tumors are malignant and have metastases at diagnosis.
- Gastrointestinal Carcinoid Tumors Treatment
- Pancreatic Cancer Treatment
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- Hochwald SN, Zee S, Conlon KC, et al.: Prognostic factors in pancreatic endocrine neoplasms: an analysis of 136 cases with a proposal for low-grade and intermediate-grade groups. J Clin Oncol 20 (11): 2633-42, 2002.
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- Gouya H, Vignaux O, Augui J, et al.: CT, endoscopic sonography, and a combined protocol for preoperative evaluation of pancreatic insulinomas. AJR Am J Roentgenol 181 (4): 987-92, 2003.
- Nikfarjam M, Warshaw AL, Axelrod L, et al.: Improved contemporary surgical management of insulinomas: a 25-year experience at the Massachusetts General Hospital. Ann Surg 247 (1): 165-72, 2008.