Lecture 7: Esophagus and Stomach Histology Flashcards
What is the first part of the GI tract according to Furth?
The brain
Thinking about the eating activates shit
What is the function of stomach and function?
- motility
- barrier
Stomach = breakdown, hormone production and intrinsic factor
What is the epithelium of esophagus?
Stratified squamous
What type of epithelium lines the FETAL esophagus? Significance?
Ciliated COLUMNAR
Same epithelium as the trachea so it shows the common derivation of trachea and esophagus
Tracheo-esophageal fistulas then can occur
Where is the last place that you can find salivary glands?
Esophagus
What types of glands can be found in esophagus?
Salivary glands
Provides lubrication and enzymes like amylase
What are developmental abnormalities of esophagus?
- atresia
- fistula (tracheal-esophageal)
- Duplication cyst
- Inlet Patch
What is a duplicatioin cyst?
Rare congenital malformations of GI tract
Duplication of the segment to which it is adjacent
Can compress the airweay
What is an inlet patch?
A congenital anomaly when gastric mucosa is present at the end of what should be the esophagus
Can lead to esophagitis when acid is secreted by the gastric mucosa
Can actually be any type of mucosa
No biologic significance in patient
What is esophagitis?
Injury to the mucosal lining of the esophagus
Neutrophils and eosinophils are there
Lymphocytes are NORMAL
Why are there lymphocytes normally there in esophagus?
Because it is part of the mucosal associated lymphoid tissue (MALT)
What are the etiologies for esophagitis?
Allergy Pill Crohns Trauma REFLUX And a shitload more
What causes reflux esophagitis?
Failure of gastro-esophageal sphincter and gastric contents come up (bile and HCl)
Why does it matter as to the “type” or etiology of esophagitis a person may have?
Because it helps with treatment
Viral inclusions vs. neutrophils vs. fungus
Such as CMV
What are the histological/gross characteristics of eosinophillic esophagitis?
Histology = eosinophils Gross = striped tiger like appearance
What are skin disorders that present as esophagitis?
- Pemphigus
- Pemphigoid
- Lichenoid reactions
Why does skin shit affect esophagus?
Because skin and esophagus have the same epithelium
What is pemphigus?
A skin disease in which watery blisters form on the skin
What is one of the most common causes of dysphagia?
A Schatzki Ring
Ingrowth of the squamous epithelium that blocks shit
What is achalasia?
HYPERmotility disorder
Lower esophageal sphincter is tight and won’t open or relax
Leads to squamous cell carcinoma progression
Esophagus will enlarge due to the blockage
What happens in connective tissue disorders like scleroderma?
Selective atrophy of inner circular muscle layer
Presents with Raynaud’s
What is a Mallory Weiss tear?
When you rip the distal esophagus causing massive bleeding
Happens after wrenching vomiting
How do you know if it is striated
vs. smooth muscle problem?
If you have trouble swallowing it is striated
What are the types of malignant tumors of the esophagus?
- adenocarcinoma
- squamous cell carcinoma
- sarcoma
- lymphoma
- melanoma
- metastatic
Can also be benign
What is number 1 in cancer deaths among GI organs?
Colo-rectal
Colo-rectal is most common of GI
In esophagus, what is most common malignant tumors?
Carcinomas
Squamous cell carcinoma is most common in world
Adenocarcinoma is most common in western countries
What is the pathogenesis of adenocarcinoma?
Reflux of acid leads to metaplasia of the esophagus
Metaplasia then leads to formation of adenocarcinoma
What is Barrett esophagus?
Glandular metaplastic mucosa (goblet cells) INSTEAD OF squamous mucosa
Patients with Barrett’s have an increased risk of progressing to esophageal adenocarcinoma
Due to reflux
10%
Over 50% of patients with barrett’s has no symptoms
i. the length of intestinal metaplasia is determined at initiation of injury (doesn’t change)
ii. short segments do not convert to long segments (so length of metaplasia is static)
iii. the risk of cancer is greater in long segment than short segment
Where should you have goblet cells in GI?
Small intestine
So if you see that somewhere else, you are fucked
Does the esophagus have a serosa?
NO, it only has an adventitia
What are the etiologic factors for squamous cell carcinoma?
- smoking
- lye digestion
- achalasia
- diverticulum
- not caused by HPV
What is the timeline of cancer diagnosis?
Squamous mucosa intestinal metaplasia Dysplasia invasion = cancer
Dysplasia only occurs in EPITHELIUM not in endothelium (so you don’t see that shit with HCC)
What is dysplasia?
Neoplastic epithelium that remains confined within basement membrane of epithelial surface
Nuclei = large, hyperchromatic, irregular contours)
What are the three glandular regions of stomach and what are their functions?
- cardia
-are of reactive changes - Corpus
-oxyntic mucosa (acid producing) - Antrum
-mucous glands predominate
NO OXYNTIC glands
Gastrin producing endocrine cells
What are the normal architecture of normal antrum?
DEVOID of MALT (because acid is all you neeed)
Flat
Makes gastrin
Motility function
What is acute gastritis?
Acute inflammation and/or erosion of gastric mucosa
Breakdown of mucosal barrier can allow luminal contents (HCL) to diffuse to lamina propia
Done by NSAIDs, EtOH, pills
What is chronic gastritis?
Chronic inflammation (lymphocytes and plasma cells) in gastric mucosa
What are the two causes of chronic gastritis?
- H. pylori
2. autoimmune gastritis
What pills can cause gastritis?
Iron pill
What does it mean to have “activity” with acute gastritis? Significance?
Activity = presence of neutrophils
Gastritis with activity suggests presence of H. pylori or bacteria
What does ATROPHIC chronic gastritis?
Loss of parietal and chief cells
How you lose them is not necessary for label
What is the significance of atrophic chronic gastritis?
- carcinoma/lymphoma evolution
2. AUTOIMMUNE etiology
What does it mean for something to be antralized?
It means your parietal and chief cells of your OXYNTIC (corpus) mucosa is killed so the histology slide looks more like the antrum than the corpus
What are antibodies attacking in autoimmune gastritis?
They attack H+ pump
What happens when you have autoimmune gastritis?
No parietal cells Hypergastrin secretion Proliferation of ECL cells “carcinoid tumors” Benign and wont kill your shit
What is the difference between H pylori and autoimmune gastritis?
H pylori starts in the antrum and moves up to corpus
Autoimmune gastritis starts from corpus (because it is where the chief cells) and moves down to antrum
What is the significance of fundic gland polyp?
It is benign with no clinical consequences
Dilatation of oxyntic and chief cells
Bigger oxyntic and chief cells
What are the key characteristics of hyperplastic gastric polyp?
Benign
Located in the antrum
Arise on some form of underlying gastritis
How can you have enlarged gastric folds?
- lymphoma
- gastric cancer
- metastatic breast lobular carcinoma
- diffuse gastritis
- true increase in gastric epithelium (hypertrophic gastrophies)
What is Menetriers Disease?
Error in TGF alpha signaling
Induces epithelial (foveolar) cell proliferation
Inhibits parietal cell acid secretion
Increases mucin production
Too much mucin = less protein available which will lead to lower serum albumin
Lower serum albumin = diarrhea
What are the two types of gastric cancer?
- Intestinal
2. Signet Ring
What are the key characteristics of intestinal type gastric cancer?
Gland formation
Repeated injury/chronic gastritis
What are the key characteristics of signet ring type?
E-cadherin
No injury/gastritis
Sporadic, so no geographic variation
What does gastric signet ring carcinoma present as?
Linitus plastic (leather bottle stomach)
What happens when you lose E-cadherin?
Loss of cell to cell adhesion
Makes cell bunch up into signet ring type shape
