Vasoactive intestinal polypeptide secreting tumors (VIPomas) are very rare pancreatic neuroendocrine tumors (PNETs) associated with profuse diarrhea . They are usually single tumors and metastatic at diagnosis. Generally, laboratory testing includes an electrolyte panel and vasoactive intestinal peptide test.
Tabs Content Clinical Overview Diagnosis
Indications for Testing
Chronic, profuse, secretory diarrhea
Criteria for Diagnosis
Documented elevated (>200 pg/mL) vasoactive intestinal polypeptide (VIP) concentration (National Cancer Institute [NCI], 2018) in patient with large-volume secretory diarrhea (Vinik, North American Neuroendocrine Tumor Society [NANETS], 2010)
VIP level >75 pg/mL highly suggestive
Large-volume diarrhea (Kulke, NANETS, 2010)
70-80% of patients with VIPoma have more than 3L/day
Virtually all patients with VIPoma have >700mL/day
Hypokalemia Achlorhydria
Laboratory Testing
Histology
Definitive diagnosis requires biopsy and pathologist examination
Useful immunohistochemical stains may include chromogranin A, synaptophysin, and cytokeratin
For detailed descriptions, including recommended tests, refer to ARUP’s Immunohistochemistry Stain Offerings
Imaging Studies
Computed tomography (CT)/magnetic resonance imaging (MRI) or endoscopic ultrasound
Somatostatin-receptor scintigraphy
Differential Diagnosis
Monitoring
Plasma chromogranin – often used to monitor functional and nonfunctional PNETs after resection (Vinik, NANETS, 2010)
Background
Epidemiology
Risk Factors
Genetic – ~5% associated with MEN1 (Jensen, 2012)
Pathophysiology
Most tumors occur in the body and tail of the pancreas and are unifocal (other locations include adrenal, paraganglia)
Symptoms result from the secretion of the peptide hormone VIP, an amino acid polypeptide that is a potent stimulator of intestinal secretion and inhibitor of gastric acid secretion
Other tumors can produce VIP – ganglioneuroblastoma, bronchogenic carcinoma , pheochromocytoma , and medullary thyroid carcinoma
Clinical Presentation
Verner-Morrison syndrome (pancreatic cholera)
ARUP Lab Tests
Initial testing in evaluation of diarrhea
Aid in the diagnosis of VIPoma
Aid in monitoring; not recommended for diagnosis of carcinoid tumors
May be useful in monitoring nonsecretory sympathetic and parasympathetic neuroendocrine tumors
Aid in histologic identification of neuroendocrine tissue
Stained and returned to client pathologist; consultation available if needed
Aid in histologic diagnosis of VIPoma
Stained and returned to client pathologist; consultation available if needed
Aid in grading of neuroendocrine tumors
Determine mitotic rate of tissue
Stained and resulted by ARUP
Aid in histologic identification of neural and neuroendocrine tissue
Stained and returned to client pathologist; consultation available if needed
Aid in the diagnosis and monitoring of PNETs
References NCCN Clinical Practice Guidelines in Oncology, Neuroendocrine and Adrenal Tumors. Version 4.2018 . National Comprehensive Cancer Network. Fort Washington, PA [Updated: May 2018; Accessed: Jul 2018]O'Toole D, Grossman A, Gross D, Fave GD, Barkmanova J, O'Connor J, Pape U, Plöckinger U, Mallorca Consensus Conference participants, European Neuroendocrine Tumor Society. ENETS Consensus Guidelines for the Standards of Care in Neuroendocrine Tumors: biochemical markers. Neuroendocrinology. 2009; 90(2): 194-202. PubMed Vinik AI, Woltering EA, Warner RR, Caplin M, O'Dorisio TM, Wiseman GA, Coppola D, Go VL, North American Neuroendocrine Tumor Society (NANETS). NANETS consensus guidelines for the diagnosis of neuroendocrine tumor. Pancreas. 2010; 39(6): 713-34. PubMed Oberg K, Knigge U, Kwekkeboom D, Perren A, ESMO Guidelines Working Group. Neuroendocrine gastro-entero-pancreatic tumors: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. Ann Oncol. 2012; 23 Suppl 7: vii124-30. PubMed Jensen RT, Cadiot G, Brandi ML, de Herder WW, Kaltsas G, Komminoth P, Scoazec J, Salazar R, Sauvanet A, Kianmanesh R, Barcelona Consensus Conference participants. ENETS Consensus Guidelines for the management of patients with digestive neuroendocrine neoplasms: functional pancreatic endocrine tumor syndromes. Neuroendocrinology. 2012; 95(2): 98-119. PubMed Pancreatic Neuroendocrine Tumors (Islet Cell Tumors) Treatment (PDQ) – Health Professional Version . National Cancer Institute. [Updated: Apr 2019; Accessed: Oct 2019]Oberg K, Couvelard A, Fave GD, Gross D, Grossman A, Jensen RT, Pape U, Perren A, Rindi G, Ruszniewski P, Scoazec J, Welin S, Wiedenmann B, Ferone D, all other Antibes Consensus Conference participants. ENETS Consensus Guidelines for Standard of Care in Neuroendocrine Tumours: Biochemical Markers. Neuroendocrinology. 2017; PubMed Falconi M, Eriksson B, Kaltsas G, Bartsch DK, Capdevila J, Caplin M, Kos-Kudla B, Kwekkeboom D, Rindi G, Klöppel G, Reed N, Kianmanesh R, Jensen RT, Vienna Consensus Conference participants. ENETS Consensus Guidelines Update for the Management of Patients with Functional Pancreatic Neuroendocrine Tumors and Non-Functional Pancreatic Neuroendocrine Tumors. Neuroendocrinology. 2016; 103(2): 153-71. PubMed Kulke MH, Anthony LB, Bushnell DL, de Herder WW, Goldsmith SJ, Klimstra DS, Marx SJ, Pasieka JL, Pommier RF, Yao JC, Jensen RT, North American Neuroendocrine Tumor Society (NANETS). NANETS treatment guidelines: well-differentiated neuroendocrine tumors of the stomach and pancreas. Pancreas. 2010; 39(6): 735-52. PubMed Educational Videos Related Topics Last Update: October 2019
