Gastric
dysplasia may present as a raised, circumscribed lesion (adenoma) or as
a flat/depressed lesion.
Adenomatous
dysplasia :
-
Precancerous condition.
- Associated with atrophic gastritis with intestinal metaplasia.
- Site: Usually antrum
- Size- About 3-4 cm in diameter
- Sessile or pedunculated lesion with a lobular surface.
- Histologically, gastric adenomas are composed of dysplastic
epithelium.
- Malignancy is related to size,dysplasia and villous growth pattern.
- On the basis of architecture, adenomas are divided into tubular,
tubulovillous and villous architecture.
- Degree of dysplasia (mild, moderate or severe) is based on nuclear
crowding , hyperchromasia, stratification & mitotic activity .
- Adenomas may show i) gastric foveolar or pyloric gland type
epithelium, ii) gastric & intestinal type features.
iii) paneth cell type (paneth cell adenoma).
- Treated by endoscopic polypectomy.
- Intramucosal adenocarcinoma in adenoma is
characterized by invasion of dysplastic epithelium into lamina propria.
Read: Early gastric carcinoma
Chronic gastritis
Gastric
epithelial dysplasia(flat/depressed) :
- Site:
Usually in gastric antrum (along lesser curvature)
- Gross
features: Ill-defined thickened and congested mucosa which may be
slightly depressed or
raised from the mucosa.
- Microscopic
features:
1. Gastric dysplasia usually arises in the backround of chronic
atrophic gastritis with immature intestinal metaplasia.
Cytological & architectural atypia, irregular nuclear hyperchromatism,
irregular nucleoli.
Composed of tall columnar cells with pale cytoplasm.
A few goblet cells are present.
Prominent budding or branching of glands.
Lack of maturation of cells.
Abrupt interphase with adjacent epithelium.
2
Gastric dysplasia of non-metaplastic foveolar epithelium
(tubule neck dysplasia) is rare . These are precursor of diffuse
type gastric carcinoma.
Grading of gastric
dysplasia:
Two tier system followed : High grade and low grade
Previously three tier system: Mild, moderate, severe.
IMAGE LINK:
Low grade dysplasia
High
grade dysplasia
Classification of gastrointestinal epithelial neoplasia:
Category I
Negative for neoplasia/dysplasia
Category 2
Indefinite for neoplasia/dysplasia
Category3
Non-invasive neoplasia low grade (low grade adenoma/dysplasia)
Category 4
Non invasive neoplasia high grade
i ) High grade adenoma/dysplasia
ii) Non-invasive carcinoma (carcinoma in situ)
iii) Suspicious of invasive carcinoma
Category 5
Invasive neoplasia
i ) Intramucosal carcinoma
ii) Submucosal carcinoma or beyond
Reference:
The Vienna classification of gastrointestinal epithelial neoplasia. Gut
2000 Aug;47 (2):251-5
|