Pancreas
Neuroendocrine neoplasms
Gastrinoma

Editor-in-Chief: Debra Zynger, M.D.
Raul S. Gonzalez, M.D.

Topic Completed: 18 July 2019

Revised: 18 July 2019

Copyright: 2019, PathologyOutlines.com, Inc.

PubMed Search: Gastrinoma[TI] OR G cell tumor[TI] pancreas

Raul S. Gonzalez, M.D.
Page views in 2018: 1,465
Page views in 2019 to date: 1,456
Cite this page: Gonzalez RS. Gastrinoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/pancreasgastrinoma.html. Accessed October 17th, 2019.
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
  • ICD10: C25.4 - malignant neoplasm of endocrine pancreas
  • ICD-O: 8153/3 - gastrinoma, malignant
Epidemiology
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 (Arch Pathol Lab Med 2000;124:832) or due to occult duodenal microgastrinomas with lymph node metastasis (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
Clinical features
  • Associated with hypersecretion of gastric acid and severe peptic ulceration
  • 90% have ulcers (85% in duodenum / jejunum, 15% in stomach)
  • One third of patients have diarrhea
  • May be metastatic at time of diagnosis
Diagnosis
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:
Missing Image

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
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:
Missing Image

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.

Nests and cords of cells


AFIP images

Malignant tumor has trabecular pattern

Lobular trabecular pattern

Positive stains
Electron microscopy description
  • Tumor cells may contain small, electron dense granules
Electron microscopy images

AFIP image

Pancreatic gastrinoma

Sample pathology report
  • Pancreas and duodenum, Whipple procedure:
    • Well differentiated neuroendocrine tumor of pancreas (see comment and synoptic report)
      • Comment: Based on the patient’s clinical symptoms, this neuroendocrine tumor is best considered a gastrinoma.
Differential diagnosis
Board review question #1
    Which of the following types of neuroendocrine tumor may arise primarily within a lymph node near the duodenum and pancreas?

  1. Gastrinoma
  2. Glucagonoma
  3. Insulinoma
  4. Somatostatinoma
  5. VIPoma
Board review answer #1
A. Gastrinoma

Comment Here

Reference: Gastrinoma
Board review question #2
    Gastrinomas arising sporadically, compared to those arising in the setting of MEN1, are more likely to be:

  1. Benign clinically
  2. Cystic
  3. Located in the pancreas
  4. Multifocal
  5. WHO grade 1
Board review answer #2
C. Located in the pancreas

Comment Here

Reference: Gastrinoma
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