Zollinger Ellison Syndrome Gastrinoma

Slide 1 · Zollinger–Ellison syndrome

Gastrinoma

Functional neuroendocrine neoplasm · Gastric pathology · MEN1

Dr Abu Suraih Sakhri

MBBS, MD (Pathology)

www.abusuraihsakhri.com

Slide 2 · Learning objectives

Identify the hormone-producing lesion and its common locations.

Explain how gastrin excess produces gastric changes and peptic ulceration.

Distinguish sporadic gastrinoma from MEN1-associated disease.

Relate morphology, localization and spread to clinical management.

Slide 3 · The lesion and the syndrome are not synonymous

Gastrinoma

Excess gastrin

Acid hypersecretion

Zollinger–Ellison syndrome

Slide 4 · Functional tumor, distant target organ

Gastrinoma: A gastrin-producing neuroendocrine neoplasm

Stomach: Exaggerated secretory and trophic response

Duodenum/jejunum: Acid-related mucosal injury

A secretory tumor can generate the dominant pathology outside its tissue of origin.

Slide 5 · Original clinicopathologic association

Endocrine tumor / islet-cell lesion

Marked gastric acid secretion

Severe peptic ulceration

Recognize all three components; The ulcer alone does not identify the tumor.

Slide 6 · Typical clinical entry points

Duodenal ulceration may be the presenting problem.

Chronic diarrhea is another common presentation.

Recurrent or unusually located ulceration strengthens suspicion.

The primary tumor may remain clinically occult.

Slide 7 · Anatomic origin is not confined to the pancreas

Duodenum

Peripancreatic soft tissue

Pancreas

Recognized locations of a gastrin-producing neoplasm

Red circles indicate possible tumor sites; Not a prevalence chart.

Frequent duodenal and peripancreatic locations as well as pancreatic tumors.

Slide 8 · The “gastrinoma triangle” is a regional concept

Duodenum

Peripancreatic tissues

Pancreas

Region in which gastrinomas may be found

Schematic localization concept — not an anatomical scale drawing or a definitive operative map.

Slide 9 · Gastrin excess drives the clinicopathologic cascade

Gastrin-secreting tumor

Hypergastrinemia

Excess acid production

Ulcers / diarrhea

Slide 10 · Hormonal hypersecretion is the initiating defect

The neoplasm secretes excess gastrin.

The syndrome is defined by systemic consequences of that excess.

Small tumor burden does not necessarily mean mild hormone effects.

Tumor size and hormone-mediated severity are separate clinical dimensions.

Slide 11 · Acid secretion is the major injurious effector

Gastrin excess

Parietal cell stimulation

High gastric acid output

Peptic mucosal damage

Slide 12 · Gastrin also acts as a trophic signal

Excess gastrin promotes mucosal cellular proliferation.

The oxyntic mucosa becomes markedly thickened.

Increased mucosal mass reinforces the acid-secretory phenotype.

The stomach changes are a hormone-driven response, not necessarily a gastric primary neoplasm.

Slide 13 · Parietal cell hyperplasia explains acid output

Parietal-cell-rich mucosa

Massive parietal cell hyperplasia

Increased oxyntic mucosal thickness

Heightened acid-secretory capacity

Schematic only; Not histologic evidence

Slide 14 · Mucous neck and endocrine cells also proliferate

Multiple mucosal cell compartments

Gastrin stimulates mucous neck cell hyperplasia.

Endocrine-cell hyperplasia accompanies the oxyntic changes.

Several cell populations contribute to mucosal thickening.

Schematic only; Not histologic evidence

Slide 15 · Oxyntic mucosal thickening: An important clue

Finding

Interpretation

Thickened oxyntic mucosa

Hormone-mediated hyperplasia

Abundant parietal cells

Increased acid-producing compartment

Ulcerated duodenum

Downstream consequence of acid excess

Slide 16 · Peptic ulceration follows excessive acid exposure

Acid hypersecretion

Increased mucosal acid burden

Mucosal injury

Ulcer formation

Slide 17 · Duodenal ulcers are a common presentation

Peptic ulcers in ZES may resemble ordinary peptic ulcers histologically.

Disease can be severe despite no unique ulcer morphology.

The clinical pattern and secretory context are critical.

Slide 18 · Jejunal ulceration is a strong warning sign

Ulcers can extend beyond usual duodenal sites.

Intractable jejunal ulcers should prompt consideration of ZES.

Location changes the diagnostic probability, not ulcer histology.

Slide 19 · Multiplicity and treatment resistance matter

Duodenal and gastric ulcers may be multiple.

Ulcers may respond incompletely to conventional therapy.

Persistent acid drive explains ongoing ulcer formation.

Successful acid blockade permits ulcer healing.

Slide 20 · Chronic diarrhea belongs to the syndrome

Diarrhea may accompany or even dominate the presentation.

It can coexist with recurrent peptic ulceration.

In the Robbins account, both reflect a gastrin-producing tumor syndrome.

Do not require ulceration as the only presenting complaint.

Slide 21 · Symptoms and morphology are connected

Source

Response

Manifestation

Gastrinoma

Gastrin excess

Acid hypersecretion

Gastric oxyntic mucosa

Cell hyperplasia

Mucosal thickening

Duodenum / jejunum

Acid-mediated injury

Peptic ulcers

Source

Response

Manifestation

Slide 22 · Gastrinoma belongs to the NEN family

Neuroendocrine neoplasms can be hormonally functional or nonfunctional.

Pancreatic neuroendocrine neoplasms differ from exocrine pancreatic tumors.

Gastrin production defines the functional identity of gastrinoma.

Slide 23 · Well-differentiated NEN versus neuroendocrine carcinoma

Feature

Well-differentiated NEN

Neuroendocrine carcinoma

Morphology

Relatively organized; often bland

Poorly differentiated

Proliferation

Graded with mitoses and Ki-67

Typically highly proliferative

Interpretation

Do not infer benign behavior

Distinct aggressive category

Slide 24 · Gastrinomas may look deceptively bland

Conceptual cellular architecture — not microscopy

Tumor cells may be monotonous with little anaplasia.

Bland nuclei cannot reliably exclude invasive behavior.

Morphology requires correlation with tumor extent and metastasis.

Schematic only; Not histologic evidence

Slide 25 · Cytologic blandness does not imply benign biology

More than half of gastrin-producing tumors are invasive or metastatic when diagnosed (Robbins).

A neat, uniform microscopic appearance can coexist with aggressive disease.

Document invasion and spread independently of bland cytology.

A central pathology pitfall: Morphology alone underestimates biological potential.

Slide 26 · Metastatic spread changes the clinical problem

Primary gastrinoma

Local invasion / metastatic spread

Persistent endocrine effects

Tumor-related morbidity

Slide 27 · Liver metastasis has major prognostic relevance

Hepatic metastases are associated with shorter life expectancy.

Progressive metastatic tumor burden may lead to liver failure.

Long-term survival depends heavily on tumor behavior after acid control.

Slide 28 · Approximately three-quarters are sporadic

75%

25%

Sporadic

MEN1-associated

Textbook proportions: Approximately 75% sporadic and 25% MEN1-associated.

Slide 29 · Sporadic lesions are generally solitary

Most sporadic gastrinomas present as a single neoplasm.

The pancreas is a recognized location in the sporadic group.

Solitary does not mean nonmetastatic or low risk.

Count and distribution assist etiologic classification, not grading.

Slide 30 · MEN1-associated lesions are often multifocal

Duodenum

Pancreas

Multiple possible duodenal primaries

A synchronous lesion can coexist

Each red circle represents a possible lesion, not a quantitative incidence estimate.

Duodenal primaries predominate in MEN1 and synchronous lesions can be present.

Slide 31 · Sporadic and MEN1-associated gastrinoma differ

Feature

Sporadic

MEN1-associated

Approximate share

75%

25%

Multiplicity

Usually solitary

Often multifocal

Typical distribution

Pancreas or duodenum

Duodenum especially common

Broader disorder

Isolated NEN

Multigland tumor syndrome

Slide 32 · The duodenum is central in MEN1

Duodenal gastrinomas greatly exceed pancreatic gastrinomas in MEN1.

Synchronous duodenal and pancreatic tumors can occur.

Small or multifocal lesions challenge complete localization.

Look beyond the most conspicuous pancreatic lesion.

Slide 33 · MEN1 involves the three classic endocrine sites

Parathyroids

Pancreas / duodenum

Pituitary

The “three Ps” are a syndrome-level clue, not a description of a single multihormonal tumor.

Slide 34 · MEN1 is a tumor-suppressor disorder

Germline MEN1 mutation

Altered menin function

Multigland neoplasia

Potential gastrinoma

Slide 35 · Menin is a regulator of transcriptional complexes

The MEN1 gene encodes menin.

Menin participates in transcription factor complexes.

Its effects depend on binding partners and cellular context.

Avoid assigning a single universal downstream pathway to menin.

Slide 36 · MEN1 causes more than gastrinoma

Organ

Common example

Clinical implication

Parathyroid

Hyperplasia / adenoma

PTH-mediated hypercalcemia

Pancreas / duodenum

Functioning NEN

ZES or hypoglycemia

Pituitary

Prolactinoma

Hormonal excess syndrome

Organ

Common example

Clinical implication

Slide 37 · Multihormonal tumor is not the same as MEN1

Multihormonal NEN

MEN1 syndrome

One tumor can secrete several hormone types

Separate neoplasms in multiple endocrine organs

Defined by hormone products of tumor

Defined by inherited multigland predisposition

May occur without inherited MEN1

Classically germline MEN1-related

Slide 38 · PanNEN grading uses proliferation, not secretion

Well-differentiated neuroendocrine neoplasms are evaluated with mitotic activity and Ki-67.

Hormone production identifies a functional subtype.

Grade and functional phenotype answer different pathology questions.

Slide 39 · Cellular monotony must be interpreted cautiously

Schematic of monotonous tumor cells

The tumor may have uniform cells and limited pleomorphism.

The gross and microscopic tumor extent still requires assessment.

Invasion or metastases override reassuring cytologic blandness.

Schematic only; Not histologic evidence

Slide 40 · Anatomic localization and tumor biology are separate

Question

Evidence needed

Where is it?

Regional localization studies

How widespread?

Extent and metastatic assessment

What does it secrete?

Clinical endocrine syndrome

How aggressive?

Differentiation, proliferation, invasion and spread

Slide 41 · When should the clinician suspect ZES?

Recurrent / refractory ulceration

Unusual jejunal ulcer site

Chronic diarrhea with ulcer disease

Consider gastrinoma / ZES

Slide 42 · Gastric biopsy and primary tumor biopsy answer different questions

Tissue examined

What it may show

Oxyntic gastric mucosa

Parietal, mucous neck and endocrine hyperplasia

Ulcer edge

Peptic injury (not specific to ZES)

Primary NEN

Tumor morphology and tumor classification

Slide 43 · Endoscopic ultrasonography supports tumor localization

Endoscopic ultrasonography is listed by Robbins among gastrinoma-localizing modalities.

Localization is needed before decisions about definitive tumor treatment.

Identification of one lesion may not exclude additional MEN1 lesions.

Localization is not a substitute for determining tumor extent.

Slide 44 · Somatostatin receptor imaging is another modality

Somatostatin receptor scintigraphy for gastrinoma localization.

The method exploits neuroendocrine tumor biology.

Imaging complements the clinicopathologic assessment.

This lecture reproduces the textbook modality without inserting unverified test-performance estimates.

Slide 45 · MEN1 requires attention to multiplicity

Suspected MEN1-associated gastrinoma

Consider duodenal and pancreatic sites

Search for multifocal tumors

Integrate multigland context

Slide 46 · Ordinary peptic ulcers can resemble ZES ulcers

Peptic ulcer disease

Zollinger–Ellison syndrome

May be clinically isolated

Caused by a gastrin-secreting tumor

Ulcers may share histologic appearance

Often multiple or difficult to treat

No endocrine tumor implied

Gastric oxyntic hyperplasia provides context

Slide 47 · Contrast with Ménétrier disease

Feature

Ménétrier disease

Zollinger–Ellison syndrome

Predominant cells

Foveolar mucous cells

Parietal + mucous neck + endocrine cells

Gastric change

Enlarged rugae, gland alterations

Thickened oxyntic mucosa

Clinical clue

Protein loss / hypoproteinemia

Marked acid production / ulcers

Slide 48 · Secretory diarrhea has other endocrine causes

Syndrome

Hormone / underlying lesion

Distinguishing context

ZES

Gastrin-producing NEN

Acid excess and peptic ulcers

VIPoma syndrome

Vasoactive intestinal peptide

Watery diarrhea, hypokalemia, achlorhydria

Slide 49 · Clinical interpretation requires three compartments

Hormone source

Gastric response

Intestinal injury

Diagnostic confidence improves when anatomic, physiologic and clinical evidence converge.

Slide 50 · Proton pump inhibitors control the acid problem

Proton pump inhibition

Reduced gastric acid secretion

Ulcer healing

Lower perforation risk

Slide 51 · Acid blockade enables definitive tumor management

Acid suppression treats the endocrine consequence.

Effective blockade permits ulcer healing and lowers ulcer-related complications.

Treatment can then concentrate on the causative gastrinoma.

Control of acid is not equivalent to eradication of the tumor.

Slide 52 · Resection targets the hormone-producing lesion

Localized resectable lesion

Excision of gastrinoma

Removal of gastrin source

Potential resolution of syndrome

Slide 53 · Metastatic disease may need additional control

Somatostatin analogues may benefit some patients with metastatic gastrinoma.

Therapy must distinguish suppression of hormone-mediated effects from control of tumor progression.

Tumor growth and liver involvement as key survival determinants.

No contemporary treatment algorithm or drug dosing is claimed here.

Slide 54 · Treat the acid burden and the neoplasm

Aim

Primary concern

Robbins-described approach

Immediate control

Acid / ulcer complications

Proton pump inhibitors

Definitive treatment

Gastrinoma

Excision where possible

Metastatic context

Persistent or progressive NEN

Selected somatostatin analogues

Slide 55 · Case 1: Recurrent severe ulcers

An adult presents with recurrent duodenal ulcers and persistent diarrhea.

Ulcers recur despite repeated symptomatic treatment.

What unifying endocrine mechanism should be considered?

Identify the tumor–hormone–organ sequence.

Illustrative teaching case — not a real patient

Slide 56 · Case 1: Clinicopathologic interpretation

Gastrinoma

Gastrin excess

High acid secretion

Duodenal ulcers + diarrhea

Slide 57 · Case 2: Multifocal endocrine disease

A patient with parathyroid disease develops difficult-to-control peptic ulceration.

Multiple small duodenal neuroendocrine lesions are identified.

Which tumor predisposition syndrome is suggested?

Explain why multiplicity and the endocrine history matter.

Illustrative teaching case — not a real patient

Slide 58 · Case 2: MEN1-associated gastrinoma

Parathyroid disease

Duodenal gastrinomas

Possible other endocrine NENs

MEN1 directs attention to multigland disease and multifocal, often duodenal tumors.

Slide 59 · Case 3: Thickened gastric folds

A gastric biopsy shows markedly increased oxyntic mucosal thickness.

There is conspicuous parietal cell expansion and refractory peptic ulcer disease.

Is the mucosal hyperplasia necessarily the primary tumor?

Separate gastric response from hormone-producing source.

Illustrative teaching case — not a real patient

Slide 60 · Case 3: Gastric response versus primary lesion

Observed lesion

Meaning

Oxyntic parietal cell hyperplasia

Trophic response to high gastrin

Gastrinoma in duodenum/pancreas

Primary source of circulating gastrin

Duodenal / jejunal ulcer

End-organ acid-related injury

Slide 61 · Clinicopathologic summary

Axis

Essential point

Tumor

Gastrin-producing neuroendocrine neoplasm

Function

Acid hypersecretion and oxyntic hyperplasia

Clinical

Ulceration, diarrhea; jejunal ulcer is a red flag

Etiology

Sporadic versus MEN1-associated

Outcome

Tumor spread, especially liver involvement

Axis

Essential point

Slide 62 · Primary references and visual provenance

Robbins, Cotran & Kumar. Pathologic Basis of Disease. 11th ed. 2026.

Chapter 24: Endocrine Pancreas — pancreatic NENs and Zollinger–Ellison syndrome (pp. 1011–1012).

Chapter 17: The Gastrointestinal Tract — Zollinger–Ellison syndrome and hypertrophic gastropathies (pp. 702–703).

Chapter 24: MEN1 syndrome (pp. 1025–1026).

All diagrams: original editable PowerPoint teaching schematics; none represents a clinical specimen.