Definition/General
Introduction:
Gastric granulomatous gastritis is a rare inflammatory condition characterized by epithelioid granulomas in the gastric wall
It may be idiopathic or associated with systemic diseases
It accounts for <1% of all gastritis cases
It requires extensive workup for underlying causes.
Origin:
Results from chronic inflammatory response to various triggers
May be associated with Crohn disease, sarcoidosis, infections (tuberculosis, histoplasmosis), or foreign body reactions
Represents cell-mediated immune response
Exact cause often remains unknown.
Classification:
Primary (idiopathic): isolated gastric involvement
Secondary: associated with Crohn disease (most common)
Infectious causes: tuberculosis, histoplasmosis
Systemic diseases: sarcoidosis, Wegener granulomatosis
Foreign body reaction.
Epidemiology:
Very rare condition (<0.1% of gastritis)
Female predominance (2:1 ratio)
Young to middle-aged adults (20-50 years)
Higher prevalence in Crohn disease patients (0.7% of CD patients)
Geographic variation based on endemic infections.
Clinical Features
Presentation:
Epigastric pain (most common)
Nausea and vomiting
Gastric outlet obstruction (antral involvement)
Weight loss and anorexia
Symptoms of underlying disease
Iron deficiency anemia.
Symptoms:
Abdominal pain (postprandial)
Dyspepsia and early satiety
Nausea and vomiting
Constitutional symptoms: fever, weight loss, fatigue
Crohn disease symptoms: diarrhea, abdominal pain
Systemic symptoms (sarcoidosis).
Risk Factors:
Crohn disease (major association)
Family history of inflammatory bowel disease
Immunosuppression
Endemic infections (tuberculosis)
Exposure to foreign materials
Previous gastric surgery.
Screening:
Upper endoscopy with multiple biopsies
Colonoscopy (Crohn disease evaluation)
CT chest/abdomen/pelvis
Tuberculosis screening: skin test, IGRA
Tissue culture and PCR
Serum ACE levels (sarcoidosis).
Master Granulomatous Gastritis Pathology with RxDx
Access 100+ pathology videos and expert guidance with the RxDx app
Gross Description
Appearance:
Mucosal thickening and rigidity
Nodular gastritis pattern
Cobblestone appearance
Mucosal ulcerations possible
Gastric outlet narrowing (antral involvement)
Mass-like lesions possible.
Characteristics:
Antral involvement most common (70% cases)
Diffuse wall thickening
Loss of normal rugal pattern
Mucosal irregularity and nodularity
Pyloric stenosis may occur
Normal appearance possible (early disease).
Size Location:
Antral predominance (70% cases)
May involve corpus and fundus
Multifocal distribution
Concurrent duodenal involvement (Crohn disease)
Segmental involvement pattern.
Multifocality:
Patchy distribution characteristic
Often transmural involvement
Associated with intestinal Crohn disease
Skip lesions typical
May involve multiple GI segments.
Microscopic Description
Histological Features:
Epithelioid granulomas (non-caseating)
Multinucleated giant cells
Chronic inflammation with lymphocytes and plasma cells
Transmural involvement
Surface epithelial ulceration
Fibrosis (chronic cases).
Cellular Characteristics:
Epithelioid cells (transformed macrophages)
Langhans-type giant cells
Foreign body-type giant cells
Lymphocytes and plasma cells
Neutrophilic infiltrate (active inflammation)
Eosinophils may be present.
Architectural Patterns:
Granulomas in all layers
Mucosal and submucosal involvement
Transmural inflammation
Crypt architectural distortion
Ulceration and regeneration
Fibrosis and scarring.
Grading Criteria:
Granuloma density: number per biopsy
Size and maturity: well-formed vs poorly-formed
Giant cell type: Langhans vs foreign body
Associated inflammation: acute vs chronic
Presence of caseous necrosis.
Immunohistochemistry
Positive Markers:
CD68 (macrophages/epithelioid cells)
CD163 (M2 macrophages)
Lysozyme (macrophages)
CD20 (B-cell component)
CD3 (T-lymphocytes)
Ki-67 (proliferation).
Negative Markers:
Acid-fast stain (excludes tuberculosis)
GMS stain (excludes fungi)
Polarization (excludes foreign material)
Viral markers (CMV, EBV)
Parasitic organisms.
Diagnostic Utility:
Confirms macrophage nature of epithelioid cells
Excludes infectious causes (AFB, fungi)
Identifies foreign material (polarization)
Assesses inflammatory composition
Rules out malignancy.
Molecular Subtypes:
Crohn-associated: transmural pattern, skip lesions
Sarcoid-type: non-caseating granulomas
Infectious type: organism identification
Foreign body type: identifiable material.
Molecular/Genetic
Genetic Mutations:
NOD2/CARD15 mutations (Crohn association)
TNF-α gene polymorphisms
IL-10 gene variants
PTGER4 gene variants
ATG16L1 mutations (autophagy pathway).
Molecular Markers:
Elevated TNF-α
Increased IL-1β and IL-6
Elevated interferon-γ
Serum ACE elevation (sarcoidosis)
Calprotectin elevation (intestinal inflammation).
Prognostic Significance:
Underlying disease determines prognosis
Crohn association: chronic course, complications
Infectious causes: respond to specific therapy
Idiopathic cases: variable course
Gastric outlet obstruction: requires intervention.
Therapeutic Targets:
Corticosteroids: first-line anti-inflammatory
Immunosuppressives: azathioprine, methotrexate
Anti-TNF agents (Crohn disease)
Antimicrobial therapy (infectious causes)
Surgical intervention (obstruction).
Differential Diagnosis
Similar Entities:
Crohn disease (gastric involvement)
Sarcoidosis
Tuberculosis
Histoplasmosis
Foreign body reaction
Lymphoma with granulomatous response
Granulomatous infections.
Distinguishing Features:
Idiopathic: isolated gastric involvement
Crohn: intestinal involvement, skip lesions
Sarcoidosis: systemic involvement, elevated ACE
TB: caseating granulomas, AFB+
Foreign body: identifiable material.
Diagnostic Challenges:
Identifying underlying cause
Distinguishing infectious from non-infectious
Adequate tissue sampling
Correlation with clinical and radiological findings
Long-term follow-up required.
Rare Variants:
Isolated gastric Crohn disease
Granulomatous gastritis with eosinophilia
Drug-induced granulomatous gastritis
Post-surgical granulomatous reaction
Associated with primary immunodeficiency.
Sample Pathology Report
Template Format
Sample Pathology Report
Complete Report: This is an example of how the final pathology report should be structured for this condition.
Specimen Information
Gastric biopsy from [site], [number] fragments
Diagnosis
Chronic granulomatous gastritis
Granulomas
Epithelioid granulomas: [number], with multinucleated giant cells
Distribution
Granulomas present in: [mucosal/submucosal/transmural]
Organisms
Acid-fast bacilli: [negative/positive], Fungi: [negative/positive]
Associated Inflammation
Chronic inflammation with [lymphocytes/plasma cells/neutrophils]
Special Studies
AFB stain: [negative/positive], GMS stain: [negative/positive]
CD68: [result], polarization: [result]
[culture/PCR]: [result if available]
Recommendations
Clinical correlation, investigate underlying systemic disease
Final Diagnosis
Chronic granulomatous gastritis, [etiology to be determined/associated with condition]