Gastropathy and Acute Gastritis

Slide 1 · Gastropathy and Acute Gastritis

Mechanisms of gastric mucosal injury and morphologic recognition

Pathology teaching lecture

Dr Abu Suraih Sakhri

MBBS, MD (Pathology)

www.abusuraihsakhri.com

Slide 2 · Learning objectives

Distinguish reactive gastropathy from neutrophil-defined gastritis.

Relate gastric mucosal defenses to the mechanisms by which they fail.

Recognize the continuum from mild injury to erosion and hemorrhage.

Interpret characteristic histologic and clinical consequences.

Slide 3 · The stomach contains functionally distinct regions

Cardia

Predominantly mucin-secreting foveolar cells and small glands.

Antrum

Mucin-secreting glands with endocrine G cells.

Body and fundus

Well-developed glands with parietal and chief cells.

Functional relevance

Antral gastrin stimulates acid secretion.

Body/fundus supply acid and digestive enzymes.

Epithelial defenses are required in every region.

Slide 4 · Gastric epithelial populations are specialized

Antrum / cardia

Foveolar cells contribute mucin to the surface barrier.

Antral G cells release gastrin.

Protective secretion is central to mucosal integrity.

Body / fundus

Parietal cells secrete gastric acid.

Chief cells produce digestive enzymes.

Strong chemical digestion coexists with protective defenses.

Slide 5 · The gastric lumen is a potentially injurious environment

Gastric luminal pH may approach 1.

The lumen is more than one million times more acidic than blood.

Acid and peptic enzymes support digestion but threaten surface cells.

Normal tissue integrity depends on multiple coordinated defenses.

Slide 6 · Gastropathy and gastritis are not synonyms

Gastropathy

Reactive epithelial injury with rare or absent inflammatory cells.

Typically associated with irritants and barrier dysfunction.

Foveolar hyperplasia may be conspicuous.

Gastritis

Gastric mucosal inflammation with neutrophils.

Neutrophils in epithelium or gland lumina signal activity.

May also show injury, erosions and hemorrhage.

Slide 7 · The term “acute” describes time, not exclusively cell type

Neutrophils can occur in both acute and chronic gastric disease.

“Active inflammation” describes a neutrophilic inflammatory pattern.

“Acute gastritis” refers to an acute-duration process.

Avoid inferring clinical duration solely from neutrophil presence.

Slide 8 · Gastric injury spans a morphologic continuum

Protected mucosa

Preserved epithelial barrier with mucus, bicarbonate and perfusion.

Reactive / inflamed mucosa

Foveolar change, edema, congestion and sometimes epithelial neutrophils.

Erosive injury

Superficial epithelial loss may be accompanied by fibrin, neutrophils and blood.

The extent of damage depends on the balance between injury and defense.

Slide 9 · Clinical expression is variable

Both gastropathy and gastritis may be clinically silent.

Symptoms can include epigastric discomfort, nausea and vomiting.

Severe injury may produce erosions, ulceration or gastrointestinal bleeding.

The histologic distinction cannot be made from symptoms alone.

Slide 10 · Gastric defense is multilayered

Luminal interface

Mucus, phospholipids and bicarbonate maintain a protected surface.

Epithelial barrier

Intercellular integrity restricts acid and enzyme back-diffusion.

Lamina propria

Mucosal blood flow brings oxygen and clears back-diffused acid.

Renewal

Surface foveolar cells are replaced rapidly after injury.

Protection is distributed

Failure in one layer stresses the others.

Prostaglandins support several layers.

Luminal acid alone does not explain injury.

Slide 11 · Four linked defenses preserve the mucosa

Surface film

Mucus + phospholipids

Near-neutral zone

Surface bicarbonate

Epithelial seal

Restricts back-diffusion

Perfusion + restitution

Nutrients, clearance, renewal

Protection fails when these functions are insufficient relative to insult.

Slide 12 · Mucus provides a physical separation layer

Foveolar cells secrete a thin mucus layer into the lumen.

Phospholipids contribute to the protective luminal surface film.

The film limits direct contact of large food particles with epithelium.

Mucus also supports a stable, bicarbonate-enriched fluid microenvironment.

Slide 13 · Luminal acidity and epithelial surface pH differ

Gastric lumen

Highly acidic milieu supports digestion.

Acid and peptic enzymes remain potentially damaging.

The lumen is not a safe environment for unprotected cells.

Epithelial surface

An unstirred mucus-associated layer traps bicarbonate.

Local pH can remain near neutral.

A steep gradient reduces acid exposure to epithelial cells.

Slide 14 · Bicarbonate protects the epithelial interface

Surface epithelium

Secretes HCO₃⁻

Unstirred film

Bicarbonate retained

Local neutralization

Limits H⁺ at surface

Epithelial survival

Cell membrane protected

Loss of bicarbonate secretion or transport reduces this protective gradient.

Slide 15 · Simplified surface defense architecture

Lumen / mucus–bicarbonate layer

Muscularis mucosae (conceptual boundary)

Interpretation

Mucus lies above an intact epithelial surface.

Gastric pits descend into mucosa.

Lamina propria and muscularis mucosae lie beneath.

Original editable schematic — simplified architecture; Not a histologic specimen.

Slide 16 · Epithelial continuity limits acid back-diffusion

Surface epithelial cells form a physical barrier to luminal contents.

The barrier restricts acid diffusion into the lamina propria.

It also limits leakage of digestive enzymes and other materials.

Loss of epithelial integrity exposes deeper tissue to corrosive injury.

Slide 17 · Rapid replacement supports epithelial restitution

Surface foveolar cells are renewed approximately every 3–7 days.

Parietal and chief cells are comparatively long-lived.

Continual renewal replaces damaged superficial epithelium.

Agents that suppress cell division may impair barrier restoration.

Slide 18 · Mucosal blood flow is an active defense

Rich capillaries

O₂ + nutrients delivered

Acid clearance

Back-diffused H⁺ removed

Cell support

Metabolism maintained

Barrier preserved

Injury limited

Ischemia weakens nutrient delivery and acid washout simultaneously.

Slide 19 · Two consequences of impaired perfusion

Oxygen deficit

Surface epithelium cannot maintain normal cell function.

Repair becomes less effective.

Barrier injury may become more likely.

Reduced acid washout

Back-diffused luminal acid persists in tissue.

A protective pH gradient becomes harder to sustain.

Damage may intensify despite unchanged luminal acid.

Slide 20 · Disease follows an imbalance, not a single insult

Damaging forces

Acid, enzymes, irritants

Defense weakened

Mucus / HCO₃⁻ / flow / repair

Epithelial injury

Reactive or inflamed mucosa

Severe extension

Erosion ± bleeding

Different exposures can converge on the same pattern of mucosal injury.

Slide 21 · Common exposures and their principal effects

Exposure

Mechanism highlighted in Robbins

Potential mucosal result

NSAIDs

Cyclooxygenase / prostaglandin suppression

Loss of multiple protective functions

Alcohol / bile

Luminal irritant exposure

Reactive epithelial injury

Caustics

Severe direct chemical injury

Pronounced mucosal damage

Radiation / chemotherapy

Direct cytotoxicity and impaired renewal

Failure of epithelial protection

Slide 22 · NSAIDs are a major cause of gastric injury

Aspirin, ibuprofen and naproxen inhibit cyclooxygenase.

NSAID injury results largely from impaired prostaglandin-mediated protection.

Both gastropathy and gastritis may occur after exposure.

Exposure history is essential when interpreting reactive gastric injury.

Slide 23 · NSAIDs impair the prostaglandin defense axis

COX inhibition

NSAID exposure

↓ PGE₂ and PGI₂

Protective mediators reduced

↓ mucosal defense

Mucus, HCO₃⁻, flow, restitution

Surface injury

Gastropathy ± gastritis

Cyclooxygenase inhibition links drug exposure to several defense failures.

Slide 24 · Prostaglandins protect through multiple effects

Luminal protection

Promote mucus output.

Promote bicarbonate output.

Support phospholipid secretion.

Tissue support

Preserve mucosal blood flow.

Facilitate epithelial restitution.

Reduced aggression

Decrease gastric acid secretion.

Act through COX-dependent synthesis.

Slide 25 · COX-1 and COX-2 both contribute to protection

COX-1

Has the larger role in mucosal protection.

Inhibition strongly compromises protective prostaglandins.

Nonselective inhibitors suppress this pathway.

COX-2

Also contributes to gastric mucosal protection.

Selective inhibition does not abolish gastric injury risk.

Selective COX-2 inhibitors can still cause gastropathy.

Slide 26 · NSAID selectivity does not confer zero gastric risk

Drug group

Examples from textbook

Teaching implication

Nonselective COX inhibitors

Aspirin, ibuprofen, naproxen

Greatest gastric injury risk in this comparison

Selective COX-2 inhibitors

Celecoxib, etoricoxib

Can still cause gastropathy or gastritis

Slide 27 · Bile is a luminal irritant

Bile is listed among common causes of gastropathy.

Exposure of gastric mucosa to bile can disturb surface protection.

Histology may show a reactive injury pattern with limited inflammation.

An exposure pattern alone does not establish a specific histologic diagnosis.

Slide 28 · Alcohol can produce direct epithelial injury

Alcohol is a common irritant associated with gastropathy.

Direct cellular damage contributes to alcohol-related gastritis.

Injury may occur without a prominent inflammatory infiltrate.

Assess the epithelial reaction and the presence of neutrophils separately.

Slide 29 · Caustic ingestion produces a different scale of injury

Acid or alkali

Harsh chemical exposure

Direct cellular injury

Loss of epithelial viability

Severe mucosal damage

Broad surface compromise

Potential hemorrhage

Erosion / ulceration

Caustics as causing severe injury; Extent is exposure-dependent.

Slide 30 · Uremia can compromise bicarbonate-related protection

Ammonium ions may inhibit gastric bicarbonate transporters.

This mechanism can contribute to gastric injury in uremic patients.

The key lesion is failure of an epithelial protective function.

The morphologic outcome overlaps with other chemical or reactive insults.

Slide 31 · A urease-dependent route to epithelial injury

Urease activity

Ammonium ion generation

HCO₃⁻ transport

Inhibition by NH₄⁺

Surface gradient

Bicarbonate defense reduced

Gastric injury

Susceptibility increased

Urease-secreting H. Pylori as an example. Detailed chronic H. Pylori gastritis is a separate topic.

Slide 32 · Aging may increase susceptibility to gastritis

Reduced mucin secretion is a proposed contributing factor in older adults.

Reduced bicarbonate secretion is another suggested mechanism.

These are proposed explanations rather than a single proven pathway.

Weakened luminal defenses increase vulnerability to ordinary irritants.

Slide 33 · High altitude highlights the oxygen requirement

High altitude

Reduced oxygen availability

Mucosal delivery

Lower tissue O₂ supply

Epithelial resilience

Defense / repair challenged

Acute gastritis

Incidence may increase

The source proposes decreased oxygen delivery as a possible mechanism.

Slide 34 · Radiation and chemotherapy damage through two routes

Direct toxicity

Radiation therapy can directly damage surface cells.

Some chemotherapy agents also injure epithelial cells.

Barrier integrity may decline rapidly.

Impaired renewal

DNA synthesis and mitotic inhibitors limit replacement of damaged cells.

Restitution cannot keep pace with injury.

Repeated damage can outstrip repair.

Slide 35 · Anti-proliferative therapy undermines epithelial renewal

Mucosal replacement requires ongoing DNA synthesis and cell division.

DNA synthesis inhibitors and mitotic inhibitors can limit renewal.

A previously manageable insult may now produce more extensive injury.

This mechanism is distinct from direct chemical damage.

Slide 36 · Classify mechanisms before interpreting morphology

Mechanism

Representative setting

Defense or injury axis

Prostaglandin loss

NSAID use

Mucus, HCO₃⁻, perfusion, restitution

Chemical cytotoxicity

Alcohol, acids / alkalis

Direct cellular integrity

Impaired turnover

Antimitotic chemotherapy

Epithelial replacement

Oxygen / perfusion limitation

High altitude; ischemic stress

Metabolism and acid washout

Slide 37 · Progression from intact epithelium to denudation

Mild disturbance

Barrier intact; Surface changes may be subtle.

Reactive / active lesion

Edema, congestion, foveolar hyperplasia ± neutrophils.

Surface breakdown

Erosion exposes lamina propria; Exudate and blood may occur.

Progression is not inevitable; The severity depends on injurious and defensive forces.

Slide 38 · Mild gastropathy may be histologically subtle

Surface epithelium can remain intact.

Lamina propria may show only modest edema and congestion.

Reactive foveolar changes are often more distinctive than inflammation.

The biopsy must be interpreted in clinical and exposure context.

Slide 39 · Lamina propria edema: A subtle tissue reaction

Lumen / mucus–bicarbonate layer

Muscularis mucosae (conceptual boundary)

Pathology context

A mild increase in stromal fluid may be apparent.

This finding is nonspecific by itself.

Assess it alongside epithelial changes and inflammation.

Original editable schematic — simplified architecture; Not a histologic specimen.

Slide 40 · Vascular congestion can accompany mild injury

Slight congestion in gastropathy and mild acute gastritis.

Congestion is not sufficient to determine the cause.

A vascular reaction can coexist with intact surface epithelium.

Neutrophil distribution remains essential for classifying gastritis.

Slide 41 · Foveolar hyperplasia indicates a reactive response

Lumen / mucus–bicarbonate layer

Muscularis mucosae (conceptual boundary)

Morphologic clues

Elongated or tortuous gastric pits.

Epithelial proliferation in response to injury.

May appear without substantial inflammatory infiltrates.

Original editable schematic — simplified architecture; Not a histologic specimen.

Slide 42 · “Corkscrew” foveolae are characteristic

Reactive foveolar hyperplasia may distort pit profiles.

Elongated and tortuous pits create a corkscrew-like appearance.

Pit architecture is interpreted together with lamina propria changes.

Architectural reaction does not itself establish active gastritis.

Slide 43 · Reactive changes and inflammatory activity are separate

Reactive epithelial component

Foveolar cell hyperplasia and tortuous pits.

Lamina propria edema and congestion.

Epithelial surface may remain intact.

Active inflammatory component

Neutrophils in epithelium or glands.

Evidence of epithelial contact by neutrophils.

May accompany reactive changes and more severe damage.

Slide 44 · Mild acute gastritis has little chronic inflammation

Only a few lymphocytes and plasma cells in the lamina propria.

An extensive chronic infiltrate is not required for an acute process.

Inflammatory activity is identified by neutrophils, not by edema alone.

Evaluate location of neutrophils, not simply their overall number.

Slide 45 · Epithelial neutrophils establish inflammatory activity

Lumen / mucus–bicarbonate layer

Red ovals = neutrophils (diagrammatic)

Muscularis mucosae (conceptual boundary)

Decisive finding

Neutrophils contact epithelial cells after crossing basement membrane.

This is abnormal anywhere in the gastrointestinal tract.

The pattern supports active gastritis rather than pure gastropathy.

Original editable schematic — simplified architecture; Not a histologic specimen.

Slide 46 · Neutrophils within gland lumina are a second clue

In gastritis, neutrophils may be present within mucosal gland lumina.

They can also lie between surface epithelial cells.

Either distribution establishes an active inflammatory component.

These findings may coexist with foveolar hyperplasia.

Slide 47 · Inflammatory activity differs from disease duration

Active inflammation

A histopathologic pattern defined by neutrophils.

May occur in short- or long-duration gastric disease.

Prefer this label for inflammatory pattern.

Acute gastritis

Refers to an acute-duration clinical / pathologic process.

May show neutrophils within surface or gland epithelium.

Duration cannot be determined by neutrophils alone.

Slide 48 · An erosion is a superficial mucosal defect

Lumen / mucus–bicarbonate layer

Red ovals = neutrophils (diagrammatic)

Superficial loss

Muscularis mucosae (conceptual boundary)

Depth of injury

Surface epithelium is lost in a limited area.

Defects remain superficial in typical acute injury.

Deep mucosal penetration is not implied by “erosion.”

Original editable schematic — simplified architecture; Not a histologic specimen.

Slide 49 · Fibrin-containing exudate accompanies erosions

As injury advances, the mucosal surface can become denuded.

Neutrophils may accumulate at the site of epithelial loss.

A fibrin-containing exudate may cover erosions.

Exudate indicates surface tissue injury rather than a purely reactive pattern.

Slide 50 · Why denudation increases bleeding risk

Epithelial loss

Surface no longer continuous

Lamina propria exposed

Fragile microvasculature near injury

Hemorrhage

Blood enters superficial defect

Luminal evidence

Dark puncta or overt bleeding

The source describes dark puncta within hyperemic mucosa when bleeding occurs.

Slide 51 · Endoscopic appearance may include dark puncta

Hemorrhage can create dark puncta in hyperemic gastric mucosa.

Visible puncta indicate a bleeding component rather than only inflammation.

The extent of injury is not reliably inferred from color alone.

Histologic depth and epithelial loss remain separate considerations.

Slide 52 · Erosion and hemorrhage define a combined pattern

Erosion

Superficial mucosal defect.

Often neutrophils and fibrin-containing exudate.

May be extensive across the surface.

Hemorrhage

Blood associated with mucosal injury.

Can produce dark puncta within hyperemic mucosa.

Can coexist with erosions in acute erosive hemorrhagic gastritis.

Slide 53 · Acute erosive hemorrhagic gastritis: Core definition

Concurrent mucosal erosion and hemorrhage constitute this pattern.

Despite wide denudation, injury is typically superficial.

A neutrophilic and fibrinous surface reaction may be present.

This is a descriptive lesion pattern, not a unique etiologic diagnosis.

Slide 54 · A morphology-based comparison

Feature

Gastropathy

Active gastritis

Dominant lesion

Reactive epithelial injury

Neutrophilic inflammation

Foveolae

Hyperplasia; tortuous profiles

May be reactive as well

Neutrophils

Rare or absent

Within epithelium / gland lumina

Additional findings

Edema, congestion

Edema, congestion; possible erosions

Slide 55 · Erosion is not identical to a chronic peptic ulcer

Erosion

Defect of the superficial mucosal surface.

Can accompany acute gastric injury.

Often heals without the deep injury of an ulcer.

Ulceration

Extends more deeply into gastric tissue than a superficial erosion.

A broader outcome in severe gastric disease.

Chronic peptic ulcer disease is addressed separately.

Slide 56 · Symptoms do not identify the microscopic category

Epigastric pain can occur in gastropathy and gastritis.

Nausea or vomiting may accompany either lesion.

Both patterns may be asymptomatic.

Histology and history provide the distinction that symptoms cannot.

Slide 57 · Bleeding manifestations reflect severity

Occult / limited injury

The mucosa may show erosion or superficial hemorrhage.

Symptoms may be absent or nonspecific.

A small injury can still have a distinctive biopsy pattern.

Clinically visible bleeding

Hematemesis indicates blood vomited from the upper GI tract.

Melena may follow upper GI bleeding.

Rarely, blood loss may be massive.

Slide 58 · Bleeding is a consequence, not a separate mechanism

Multiple insults can converge on erosion and hemorrhage.

The same lesion may result from chemical, drug-related or vascular injury.

Interpret bleeding in conjunction with mucosal depth and cause.

Do not equate all gastric bleeding with primary peptic ulcer disease.

Slide 59 · A structured biopsy-reading approach

Inspect surface

Intact or eroded?

Assess foveolae

Normal or hyperplastic?

Inspect stroma

Edema / congestion?

Find neutrophils

Epithelium or glands?

Report a reactive pattern separately from neutrophil-defined activity.

Slide 60 · Histologic language: What each observation supports

Finding

Supported interpretation

What it does not prove

Corkscrew foveolae

Reactive epithelial change

Acute inflammation by itself

Lamina propria edema

Mild tissue injury

Specific exposure or cause

Intraepithelial neutrophils

Active gastritis

Duration of the process

Erosion plus blood

Erosive hemorrhagic injury

Single unique etiology

Slide 61 · Case: Epigastric discomfort after frequent analgesics

Clinical scenario

An adult taking frequent ibuprofen develops epigastric discomfort. A gastric biopsy shows elongated, tortuous foveolae and congestion; Neutrophils are scarce.

Is this pattern better termed gastropathy or active gastritis?

Identify the feature that would be needed to call the lesion active.

Slide 62 · Case interpretation: NSAID-associated gastropathy

Scant neutrophils favor gastropathy rather than active gastritis.

Reactive foveolar hyperplasia supports epithelial injury.

NSAID exposure can suppress protective prostaglandin pathways.

The drug association is clinically plausible, but biopsy alone does not prove causation.

Slide 63 · Case: Acute bleeding and superficial defects

Clinical scenario

A patient presents with hematemesis. The gastric mucosa has hyperemic areas with dark puncta. Biopsy reveals superficial epithelial defects, neutrophils and fibrinous exudate.

What morphologic diagnosis best describes the combined findings?

Distinguish the observed lesion pattern from an etiologic attribution.

Slide 64 · Case interpretation: Erosive hemorrhagic gastritis

Superficial epithelial loss establishes erosion.

Dark puncta and extravasated blood indicate hemorrhage.

Neutrophils and surface exudate support active injury.

Cause requires medication, exposure and clinical-context assessment.

Slide 65 · Relationship to neighboring gastric pathology topics

This lecture

Adjacent focused lecture

Boundary of coverage

Reactive / acute mucosal injury

Stress-related mucosal disease

Severe systemic stress and stress ulcers

Activity rather than chronicity

H. pylori gastritis

Chronic infection pattern and its consequences

Superficial erosion

Peptic ulcer disease

Deeper persistent peptic ulceration

Slide 66 · Integrative summary: Defense → reaction → loss

Defense maintained

Mucus, HCO₃⁻, epithelium, perfusion and renewal offset luminal damage.

Injury outweighs defense

Reactive epithelial changes develop; Neutrophils distinguish active gastritis.

More severe injury

Erosion, fibrinous exudate and hemorrhage may occur.

Etiology and morphologic pattern must be analyzed separately.

Slide 67 · Application question: Choose the decisive finding

Clinical scenario

Two biopsies show foveolar hyperplasia and lamina propria edema. Only one has neutrophils in the surface epithelium.

Which biopsy is active gastritis, and why?

Answer using the definition of inflammatory activity, not clinical duration.

Slide 68 · Answer: Neutrophil–epithelium contact defines activity

The biopsy with intraepithelial neutrophils has active gastritis.

Both specimens may show reactive epithelial injury.

Edema and foveolar hyperplasia alone do not establish activity.

Neutrophils do not establish how long the disease has been present.

Slide 69 · References and related reading

Robbins, Cotran & Kumar: Pathologic Basis of Disease, 11th ed. (2026). Chapter 17, “The Gastrointestinal Tract,” pp. 696–697.

Primary section: Gastropathy and Acute Gastritis, pp. 696–697.

Textbook Figure 17.13 reviews mechanisms of gastric mucosal injury and protection.

Related sections: stress-related mucosal disease, H. pylori gastritis and peptic ulcer disease.