Chapter 7 - Stomach & Duodenum Flashcards
What are the three zones of the stomach?
Cardia
Fundus/body
Antrum
Distinguish between antral and oxyntic mucosa.
Antral: Loosely packed, mucinous glands which occupy about half of the epithelial thickness.
Oxyntic: Tightly packed, with parietal (pink) and chief (purple) cells, which occupy 3/4 of the epithelial thickness
Which endocrine cells can be seen in the gastric body and antrum?
How can they be stained?
Body: Enterochromaffin-like cells
Antrum: Mixed gastrin, enterochromaffin, somatostatin.
All should stain for chromogranin.
What color is normal stomach, generally?
What would goblet cells represent?
Pink; purple/blue indicates inflammation.
Intestinal metaplasia, a marker of chronic irritation.
What mucosal histology does gastric cardia feature?
What endocrine cells does it feature?
Antral, or at least very similar to it.
No endocrine cells are seen.
What inflammatory cells are OK in the stomach? Which indicate pathology?
Some lymphoplasmacytic or eosinophilic infiltrate is okay.
Dense lymphoplasmacytic infiltrate = chronic gastritis
Neutrophils = acute gastritis
Describe the morphologic appearance of H. Pylori gastritis.
How can the organisms be visualized?
Neutrophils, chronic gastritis, and lymphoid follicles. Rod organisms in the pit lumens or on the surface of crypts.
Visible on H&E but better seen on diff-quik or giemsa. IHC?
What causes MALT lymphoma in the stomach?
How does it appear?
Chronic H. Pylori infection.
Sheets of monocytoid B cells (fried egg-like) and lymphoepithelial lesions.
Describe the appearance of foveolar hyperplasia. What does it represent?
Papillary and corkscrewed surface and pits due to proliferation of surface mucin cells. The mucin cells themselves lose mucin.
Represents chemical irritation, usually from bile or NSAIDs.
What are two forms of atrophic gastritis? How do they appear?
What should atrophy be accompanied by?
H. Pylori gastritis: Loss of glands in setting of active chronic gastritis and intestinal metaplasia with pit abscesses
Autoimmune gastritis: Loss of parietal cells with compensatory G-cell hyperplasia.
Atrophy should be accompanied by intestinal metaplasia and inflammation.
How does MALT lymphoma usually appear? What stains are helpful?
Usually monocytoid in appearance.
CD20+, CD43+ (also stains T-cells, subtract the CD3+ cells).
Describe the appearance of gastric ulcers.
How can reparative glands be distinguished from carcinoma?
Full-thickness defect of epithelium down to the muscularis with fibrinopurulent exudate.
Reparative glands have small, reactive nuclei, in a streaming parallel arrangement.
Name several causes for gastric ulcers.
Cancer
H. Pylori
NSAIDs, chemical injury
Burns
Severe stress
Name 3 gastric polyps and describe their appearances.
Fundic gland polyp: Oxyntic mucosa with cystically dilated glands. Sporadic in older patients.
Hyperplastic polyps: Elongated, cystic with mild inflammation in a background of gastritis.
Adenomas: Neoplastic and dysplastic nodule, can be gastric-type (benign) or intestinal (eg TA)
How does dysplasia in the stomach appear?
Like in the colon; hyperchromatic and pleomorphic with high N:C ratio and crowding/pseudostratification.
Describe the appearance of intestinal-type gastric adenocarcinoma.
Associated with atrophy and intestinal metaplasia, usually quite easy to spot.
Describe the appearance of diffuse-type gastric adenocarcinoma.
Signet-ring (foamy, macrophage-like) cells that infiltrate through the entire stomach causing linitis plastica.
What lesions can be found in the gastric submucosa?
Heterotopic pancreas
GIST
Leiomyomas
Carcinoids
What cells do GISTs arise from?
How can they be distinguished from leiomyomas?
From what conditions can carcinoids arise?
GIST arises from the interstitial cell of Cajal
Immunostaining for c-KIT and not smooth muscle markers
Sporadic in response to autoimmune gastritis, or in association with MEN syndromes
What are some indications for duodenal biopsies?
Gastritis / duodenitis
Ulcers
Malabsorption
Mass lesions
Describe the normal histologic appearance of duodenum.
Narrow villi with intestinal-type epithelium and inflammatory infiltrate. Submucosal Brunner’s glands.
What is Chronic peptic duodenitis? Describe its morphology.
As a response to gastritis and acid hypersecretion, the duodenum may undergo gastric metaplasia. Also can have Brunner’s gland hyperplasia (mucosal!), inflammation, and ulceration.
What is the classic picture of celiac disease?
Why will you rarely see this?
Flattened mucosa with total loss of villi and a low cuboidal epithelium.
Many people without disease are being biopsied because of serology, and those who have the disease often control their gluten intake, reducing the phenotype.
What infections can appear in the duodenum, and how do they appear?
H. Pylori
Giardia (hides in luminal debris)
MAC (foamy histiocytes in the lamina propria)
Whipple’s disease (foamy histiocytes in the lamina propria! PAS+ granules and G+ rods)
What tumors can be seen in the duodenum?
Tubular adenomas
Carcinoid tumors
Lymphoma (usually MALT type)
Left: Oxyntic mucosa, with parietal and chief cells (arrow)
Right: Antral mucosa, with mucinous glands (arrow) and foveolar epithelium (arrowhead)
H. Pylori gastritis
Arrow: Dens inflammatory infiltrate in the lamina propria
Arrowheads: Neutrophils in the surface epithelium (active)
Chemical gastritis
Edematous lamina propria with corkscrewed hyperplastic glands (arrowhead) and thin strands of smooth muscle (arrow)
Autoimmune gastritis
- Intestinal metaplasia
- Replacement of glands by mucinous antral-type
- Residual oxyntic mucosa
MALT lymphoma
Sheets of lymphocytes dissecting into muscle (arrow)
Inset: Lymphoepithelial lesions with destruction of glands by lymphocytes
Reparative changes in an ulcer
Arrow: Glands streaming in parallel with normal nuclear size.
Fundic gland polyp
Note oxyntic-type glands with some cystic dilation (circle)
Hyperplastic polyp
Arrow: Corkscrew glands and hyperplastic foveolar epithelium.
Signet ring carcinoma
Circle: Signet ring cell with large vacuole
Arrowheads: Additional infiltrating cells with large hyperchromatic nuclei.
Chronic peptic duodenitis
Arrow: Gastric metaplasia
Arrowhead: Chronic inflammation and brunner’s gland hyperplasia
Celiac disease
Note blunted villi, lamina propria inflammation (arrow), and intraepithelial lymphocytes (arrowhead)
Duodenal adenoma
Arrow: Low grade dysplasia with crowded hyperchromatic nuclei
Arrowhead: Normal duodenal mucosa
