Gastritis

Gastritis refers to an inflammatory process that affects the stomach.

Gastritis
Diagnosis in short
LM	acute: PMNs in the lamina propria or intraepithelial; (usual) chronic: cluster of plasma cells (mild), several clusters (moderate), +/-mucosal erosions (severe); lymphocytic: intraepithelial lymphocytes
Subtypes	acute gastritis, chronic gastritis, focal acute gastritis (pill gastritis), lymphocytic gastritis
LM DDx	Helicobacter gastritis, collagenous gastritis, Crohn's disease, intestinal metaplasia of the stomach, gastric columnar dysplasia, gastric carcinoma
Stains	Diff-Quik -ve, cresyl violet -ve
IHC	Helicobacter -ve
Site	stomach
Associated Dx	intestinal metaplasia of the stomach - esp. in chronic gastritis
Prevalence	very common
Blood work	H. pylori -ve or previously +ve
Endoscopy	erythema
Prognosis	good
Other	neg. Helicobacter breath test
Clin. DDx	reactive gastropathy

There are several types of gastritis:

• Helicobacter pylori gastritis.
• Collagenous gastritis.
• Acute gastritis.
• Chronic gastritis.

This article deals with acute gastritis and chronic gastritis without an apparent histologic cause.

General

• Very common.
• A specific cause is uncommonly identified histologically.

Etiology

Gastritis causes:

• Infectious:
  • H. pylori infection.
  • Tuberculosis.
  • Salmonellosis.
  • CMV.
• Endocrine-related:
  • Pernicious anemia.
  • Diabetes mellitus - gastric atony.
• Trauma, e.g. NG tube.
• Vascular, ischemia.
• Autoimmune:
  • Crohn's disease.
• Toxins:
  • Alcohol.
  • Medications, especially NSAIDs.
  • Uremia.
  • Smoking (heavy).
• Radiation.

Endoscopic appearance

• Erythematous.

Microscopic

• Inflammatory cells - see below.

Acute gastritis

• AKA active gastritis.

Features:

• Neutrophils - especially when intraepithelial.

Focal active gastritis

DDx:

1. Drugs, esp. NSAIDs.
2. Infectious.
3. Inflammatory bowel disease.

Chronic gastritis

Features:

• Plasma cells (in lamina propria).
  • Various criteria:
    1. Two plasma cells kissing, i.e. two plasma cells touching/overlapping.
    2. Three is a crowd, i.e. three plasma cells in close proximity.

Note:

• Approximately 20% of cases with an inflamed cardia will have intestinal metaplasia.

Lymphocytic gastritis

General

The DDx is limited:

1. Helicobacter gastritis.
2. Celiac disease.
3. NSAIDs.^{[citation needed]}
4. Idiopathic.
5. HIV/AIDS.

Microscopic

Features:

• 25 lymphocytes / 100 epithelial cells.

Sydney criteria for gastritis

A bunch of pathologists in Sydney came-up with criteria... and these were revised in Houston.

Classification

Updated Sydney classification:

Feature	Non-atrophic Helicobacter	Atrophic Helicobacter	Autoimmune
Inflammation pattern	antral or diffuse	antrum & corpus, mild inflammation	corpus only
Atrophy & metaplasia	nil	atrophy present, metaplasia at incisura	corpus only

Notes:

• Corpus = gastric body.
• Incisura = angular incisure, incisura angularis (Latin) - notched transition point on lesser curvature of the stomach between pylorus and body.

Severity

The Sydney group suggests grading severity with the following language:

• Mild.
• Moderate.
• Marked.

These terms are applied to the parameters described in a biopsy. The Sydney criteria lists H. pylori, neutrophils, mononuclear cells, antrum (atrophy), corpus (atrophy) and intestinal metaplasia. The paper that discusses this also give a visual analogue scale.

Parameters & Severity (adapted from Dixon et al.):

Feature	Mild	Moderate	Marked
H. pylori	few touching	many touching	piles
Neutrophils	few	bunches	crowded
Mononuclear cells	not touching	kissing	partying

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Minimal chronic inactive

STOMACH, BIOPSY: 
- BODY AND ANTRAL-TYPE GASTRIC MUCOSA WITH MINIMAL CHRONIC INACTIVE INFLAMMATION. 
- NEGATIVE FOR HELICOBACTOR-LIKE ORGANISMS. 
- NEGATIVE FOR INTESTINAL METAPLASIA. 
- NEGATIVE FOR DYSPLASIA AND NEGATIVE FOR MALIGNANCY.

Mild chronic inactive

STOMACH, BIOPSY: 
- BODY AND ANTRAL-TYPE GASTRIC MUCOSA WITH MILD CHRONIC INACTIVE INFLAMMATION. 
- NEGATIVE FOR HELICOBACTOR-LIKE ORGANISMS. 
- NEGATIVE FOR INTESTINAL METAPLASIA. 
- NEGATIVE FOR DYSPLASIA AND NEGATIVE FOR MALIGNANCY.

Moderate chronic active

STOMACH, BIOPSY: 
- BODY AND ANTRAL-TYPE GASTRIC MUCOSA WITH MODERATE CHRONIC ACTIVE INFLAMMATION. 
- NEGATIVE FOR HELICOBACTOR-LIKE ORGANISMS. 
- NEGATIVE FOR INTESTINAL METAPLASIA. 
- NEGATIVE FOR DYSPLASIA AND NEGATIVE FOR MALIGNANCY.

Micro - inactive

The sections show gastric body type mucosa with small clusters of plasma cells. There are no intraepithelial neutrophils. Goblet cells are not identified. The epithelium matures normally to the surface. No Helicobacter organisms are seen.

See also

• Helicobacter pylori gastritis.
• Collagenous gastritis.