Pancreas
Neuroendocrine neoplasms
Gastrinoma
Author: Raul S. Gonzalez, M.D.
Editor-in-Chief: Debra L. Zynger, M.D.
Last author update: 17 February 2021
Last staff update: 30 August 2022
Copyright: 2019-2024, PathologyOutlines.com, Inc.
PubMed Search: Gastrinoma pancreas pathology
Table of Contents
Definition / general | Essential features | Terminology | ICD coding | Epidemiology | Sites | Pathophysiology / etiology | Etiology | Clinical features | Diagnosis | Radiology description | Radiology images | Prognostic factors | Case reports | Treatment | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Negative stains | Electron microscopy description | Electron microscopy images | Sample pathology report | Differential diagnosis | Board review style question #1 | Board review style answer #1 | Board review style question #2 | Board review style answer #2Cite this page: Gonzalez RS. Gastrinoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/pancreasgastrinoma.html. Accessed April 24th, 2024.
Definition / general
- Pancreatic well differentiated neuroendocrine tumor that causes clinical symptoms secondary to secretion of gastrin
Essential features
- Functionally active and usually aggressive neuroendocrine tumor
- Gastrin secretion causes Zollinger-Ellison syndrome
- May occur sporadically or in the setting of MEN1
Terminology
- Pathology diagnosis should be well differentiated neuroendocrine tumor, as gastrinoma is a clinical determination
- Sometimes called G cell neoplasm
ICD coding
Epidemiology
- Roughly 20% of functional pancreatic neuroendocrine tumors are gastrinomas, though only about 5% of overall pancreatic neuroendocrine tumors are gastrinomas (Surg Pathol Clin 2014;7:559, World J Gastroenterol 2006;12:5440)
Sites
- Gastrinomas are more common in duodenum than in pancreas
- Rare examples of so called primary lymph node gastrinoma can occur:
- Gastrin producing tumors in lymph nodes with no GI or pancreatic primary, generally in patients with MEN1 (Am J Surg Pathol 2008;32:1101)
- Occur in gastrinoma triangle: from cystic and common bile ducts to the second and third portion of the duodenum to neck and body of the pancreas
- May be due to gastrin secreting neuroendocrine cells within these nodes or due to occult duodenal microgastrinomas with lymph node metastasis (Arch Pathol Lab Med 2000;124:832, Am J Surg Pathol 2008;32:1101)
Pathophysiology / etiology
- Hypersecretion of gastrin stimulates secretion of gastric acid by parietal cells, leading to ulcer formation
Etiology
- 80% of cases are sporadic; 20% are familial due to MEN1 (Hepatogastroenterology 2005;52:1668)
Clinical features
- Associated with hypersecretion of gastric acid and severe peptic ulceration
- 90% have ulcers (85% in duodenum / jejunum, 15% in stomach)
- 33% of patients have diarrhea
- May be metastatic at time of diagnosis
Diagnosis
- Glucagon provocative test is useful (Surg Today 2013;43:1281)
Radiology description
- Highly vascular and well circumscribed, as with other neuroendocrine tumors of pancreas
- Imaging may detect positive lymph nodes within the gastrinoma triangle (Diagn Interv Imaging 2016;97:1241)
- Octreotide scans have high sensitivity
Radiology images
Images hosted on other servers:
CT of pancreatic gastrinoma
Prognostic factors
- Sporadic tumors are usually solitary, aggressive and located in pancreas
- MEN1 cases are often multicentric, less aggressive and arise in duodenal wall (Gut 2007;56:606)
Case reports
- 25 year old woman with mass blocking the pancreatic duct (Surgery 2005;138:111)
- 37 year old woman with von Hippel-Lindau syndrome and 2 pancreas lesions (Rev Esp Enferm Dig 2017;109:154)
- 68 year old woman with abdominal pain and diarrhea (Oncol Lett 2016;11:3433)
- 73 year old man with pancreatic gastrinoma and endobronchial metastasis (Am J Respir Crit Care Med 2012;185:590)
Treatment
- H2 blockers for symptom management
- Surgical resection of tumor
Gross description
- Single or multiple lesions, most commonly in head of pancreas
- Firm, homogeneous, well circumscribed
Gross images
AFIP images
Lymph node gastrinoma
Microscopic (histologic) description
- Nests of monotonous low grade neuroendocrine cells with salt and pepper nuclei and ample amphophilic cytoplasm, as with any other well differentiated neuroendocrine tumor
- Associated with pancreatic polypeptide cell hyperplasia (Hum Pathol 1997;28:149)
- Nonneoplastic pancreas may show large islets and nesidioblastosis
Microscopic (histologic) images
Contributed by Raul S. Gonzalez, M.D. and AFIP images
Nests and cords of cells
Malignant tumor has trabecular pattern
Lobular trabecular pattern
Positive stains
- Gastrin (though this does not establish the diagnosis)
- Synaptophysin, chromogranin
- PDX1, INSM1 (Am J Surg Pathol 2012;36:737)
Negative stains
Electron microscopy description
- Tumor cells may contain small, electron dense granules
Electron microscopy images
AFIP images
Pancreatic gastrinoma
Sample pathology report
- Pancreas and duodenum, Whipple procedure:
- Pancreatic neuroendocrine tumor, WHO grade 2 (see synoptic report and comment)
- Comment: The patient’s clinical history of Zollinger-Ellison syndrome is noted. This may be due to gastrin secretion by this tumor, which would make it a gastrinoma. Immunohistochemical stains for synaptophysin and chromogranin are positive and the Ki67 index is approximately 4.5%.
Differential diagnosis
- Nongastrin secreting pancreatic neuroendocrine tumor:
- No histopathologic differences
- Must be determined on clinical grounds
Board review style question #1
- Which of the following types of neuroendocrine tumor may arise primarily within a lymph node near the duodenum and pancreas?
- Gastrinoma
- Glucagonoma
- Insulinoma
- Somatostatinoma
- VIPoma
Board review style answer #1
Board review style question #2
- Gastrinomas arising sporadically, compared to those arising in the setting of MEN1, are more likely to be
- Benign clinically
- Cystic
- Located in the pancreas
- Multifocal
- WHO grade 1
Board review style answer #2
