Chapter 17: Stomach Flashcards
1
Q
What differentiates Acute Gastritis from Gastropathy?
Causes of each?
A
- Acute gastritis: when neutrophils are present; autoimmune or H.pylori
- Gastropathy: absence of inflammatory cells; NSAIDs, EtOH, Bile, Stress
2
Q
Ulcers associated with acute and chronic gastritis may include layers of what type of injury? (hint: mnemonic to remember layers)
A
- Necrotic debris
- Inflammation
- Granulation tissue
- Scar (fibrosis)
*NIGS
3
Q
NSAIDs contribute to gastritis by inhibiting what?
A
COX dependent synthesis of prostaglandin E2 and I2
4
Q
Presence of _________ above the basement membrane in direct contact w/ epithelial cells is abnormal in all parts of the GI tract and signifies active inflammation (gastritis)
A
Neutrophils
5
Q
What is the charactestic profile of foveolar cells and the epithelium in acute gastritis?
A
- Foveolar cell hyperplasia w/ corkscrew profiles
- Epithelial proliferation
6
Q
Can gastropathy and acute gastritis be distinguished clinically?
A
No
7
Q
How is the response to PPI’s different if the patient is suffering from NSAID-induced gastropathy vs. pain associated w/ bile reflux?
A
- NSAID-induced may be asymptomatic or have persistent epigastric pain that responds to antacids or PPI’s
- Bile reflux is typically unresponsive to such therapies and may have occasional bilious vomiting
8
Q
Stress ulcers are most common in individuals with what 3 things?
A
1) Shock
2) Sepsis
3) Severe trauma
9
Q
Ulcers occuring in the prox. duodenum and associated with burns or trauma are called?
A
Curling ulcers
*Think curling irons will burn you!
10
Q
Gastric, duodenal, and esophageal ulcers arising in persons w/ intracranial disease are termed?
These lesions are caused by direct stimulation of?
Carry a high incidence of?
A
- Cushing ulcers
- Direct stimulation of vagal nuclei –> hypersecretion of gastric acid
*Carry a high incidence of perforation
11
Q
How does ischemia play a role in the pathogenesis of stress-related gastric mucosal injury?
A
- Systemic hypotension –> decreased blood flow due to stress-induced splanchnic vasoconstriction
- Upregulation of inducible NOS
- Increased release of vasoconstictor endothelin-1
12
Q
Absence of what morphologically in stress-related gastric mucosal injury differs it from chronic peptic ulcers?
A
Absence of scarring and blood vessel thickening (characteristic of chronic)
13
Q
What is a Dieulafoy lesion caused by and what can it lead to?
Where are they most often seen?
Bleeding is often associated with?
A
- Improper branching of submucosal artery w/i wall of stomach
- Mucosal artery 10x normal size
- Most commonly along lesser curvature, near GE junction
- May erode overlying epi and cause gastric bleeding, often assoc. w/ NSAIDs
14
Q
Gastric antral vascular ectasia (GAVE) can be recognized endoscopically how?
A
- Longitudinal stripes of edematous erythematous mucosa alternating w/ less severely injured, paler mucosa
- “Watermelon stomach”
15
Q
While often idiopathic, gastric antral vascular ectasia (GAVE) can be associated with what underlying pathologies?
Patients may present how?
A
- Cirrhosis and Systemic Sclerosis
- Present w/ occult fecal blood and iron deficiency anemia
16
Q
Most common cause of chronic gastritis?
Morphology of this organism?
A
- H. pylori
- Spiral-shaped, curved bacilli
17
Q
How does atrophic gastritis caused by H. pylori differ from chronic gastritis?
A
Has a mutlifocal pattern of injury
18
Q
Who is the primary carrier of H. pylori and how is it transmitted?
A
- Humans
- Fecal-oral
19
Q
H. pylori infection most often presents predominantly as a?
Acid production?
A
- Antral gastritis
- Normal or increases acid production
20
Q
When inflammation caused by H. pylori is limited to the antrum there is an increased risk of?
A
Duodenal peptic ulcer
21
Q
If gastritis progresses to invovle the gastric body or fundus, it’s known as?
What is seen morphologically?
Increases risk for?
A
- Multifocal atrophic gastritis
- Patchy mucosal atrophy
- Reduced parietal cell mass –> Decreased acid secretion
- Increased risk of gastric adenocarcinoma (intestinal metaplasia)
22
Q
The virulence of H. pylori is related to which 4 charactersitc features of the organism?
A
- Flagella -> allows for motility
- Urease -> generates ammonia and increases pH (for survival)
- Adhesins -> enhance bacterial adherence to surface foveolar cells
- Toxins -> such as CagA
23
Q
Which virulence factor of H. pylori is associated w/ elevated gastric cancer risk and allows for colonization of gastric body causing multifocal atrophic gastritis?
A
CagA gene
24
Q
Polymorphisms of which immunologic mediators are associated w/ development of pangastritis, atrophy, and gastric cancer associated w/ H. pylori?
A
- Increased: TNF and IL-1β
- Decreased: IL-10 (anti-inflammatory)
25
Which vitamin deficiency is a risk factor for *H.pylori*-associated gastric cancer?
Iron
26
Intraepithelial ___________ and subepithelial _________ are characteristic of *H. pylori* gastritis.
Intraepithelial **neutrophils** and subepithelial **plasma cells** are characteristic of *H. pylori* gastritis.
27
*H. pylori* displays trophism for which cells and part of stomach?
Gastric epithelia --\> antrum
28
Intense *H. pylori* infection can lead to inflammatory infiltrates producing what finding that mimics appearance of early cancer?
Thickened **rugal folds**
29
Lymphoid aggregates, some with germinal centers are frequently present in *H. pylori* gastritis and represent an induced form of?
Potential to transform into?
- Induced form of **MALT**
- **Lymphoma**
30
Pit abscesses often seen with *H. pylori* gastritis is due to a buildup of?
Neutrophils
31
*H. pylori* can be stained with?
Warthin-Starry **silver stain**
32
Which characteristics of this image are distinguishing features of *H. pylori* gastritis?
- Lymphoid aggregates w/ **germinal centers**
- Abundant **subepithelial** **plasma cells** in **superficial lamina propria**
33
Which tests can be used in the diagnosis of *H. pylori* infection?
- anti-*H.pylori* Abs test
- Fecal bacterial detection
- Urease breath test
34
Effective treatment for *H. pylori* infection includes combinations of?
Antibiotics and PPIs
35
How does the location of autoimmune gastritis differ from that of *H. pylori?*
Typically spares the antrum and **affects the body**
- Associated w/ **hypergastrinemia**
36
Autoimmune gastritis is characterized by 5 findings (i.e., Abs and deficiencies)?
- Abs to **parietal cells** and **IF**
- Reduced serum **[pepsinogen I]**
- Endocrine cell hyperplasia
- Vit B12 deficiency (due to Abs against IF)
- Defective gastric acid secretion (achlorhydria) --\> **hypergastrinemia**
37
What type of anemia is associated with autoimmune gastritis?
- Pernicious (megaloblastic) anemia
- Due to loss of IF and decreased absorption of B12
38
How is the atrophy of autoimmune gastritis different from that of *H. pylori-mediated?*
- Autoimmune causes **DIFFUSE** atrophy = **achlorhydria**
- *H. pylori* causes **mulitfocal (patchy)** = **NO** achlorhydria
39
Destruction of parietal cell components, including H+,K+-ATPase by what are considered to be the principal agents of injury in autoimmune gastritis?
**CD4+ T cells**
40
Autoantibodies to which parietal cell components are most prominently seen in autoimmune gastritis?
Do they cause damage?
- H+, K+-ATPase
- Proton pumps
- IF
\***Not pathogenic**, because neither secreted IF or proton pumps are accessible to circulating antibodies
41
Diffuse mucosal damage of the oxyntic (acid-producing) mucosa within the body and fundus of the stomach are characteristic of?
Autoimmune gastritis
42
What are some of the characteristic findings morphologically in autoimmune gastritis?
i.e., mucosa, inflammatory rxn, suface changes, and presence of which cells?
- **Thinned mucosa** and loss of rugal folds **2' to atrophy**
- **Deeper** inflammatory rxn and centered on the gastric glands
- Small surface elevations representing **intestinal metaplasia**, presence of **goblet cells** and **columnar absorptive cells**
43
Which stain can allow for visualization of endocrine hyperplasia associated w/ autoimmune gastritis?
Immunostains for **chromogrannin A**
44
What are the main inflammatory infiltrates seen with autoimmune gastritis?
Lymphocytes, macrophages, and plasma cells
45
What is the progression of autoimmune gastritis like and what is the median age of diagnosis?
Which sex is more affected?
- Progression to gastric atrophy occurs over **20-30 years**
- Median age = 60 yo
- Slightly more women affected (as w/ most autoimmune dz)
46
Sometimes the clinical presentation of autoimmune gastritis is linked to sx's of anemia (B12 deficiency), what may the patient present with?
- Atrophic glossitis (**smooth and beefy red tongue**)
- Epithelial megaloblastosis
- Malabsorptive diarrhea
- **Peripheral neuropathy --\>** paresthesias + numbness
- Spinal cord lesions --\> **Subacute combined degeneration** (loss of dorsal/lateral spinal tracts)
47
What can be corrected in regards to B12 deficiency thru B12 replacement therapy?
- **ONLY anemia**
- Neuro changes CANNOT be corrected!
48
Eosinophilic gastritis most commonly affects what part of stomach?
Increased serum levels of?
Associated w/ allergic rxns in children to what?
- Antral or pyloric regions
- Increased serum IgE levels
- Cow's milk or soy protein
49
Lymphocytic gastritis (Varioliform Gastritis) is sometimes associated w/ what underlying disease?
Most often in which gender presenting with what sx's?
- Celiac Disease
- **Women** presenting w/ **non-specific abdominal sx's**
50
What is the distinctive endoscopic appearance of Lymphocytic gastritis (Varioliform Gastritis)?
Histologically there is an increase in the # of which immune cells?
**- Thickened folds** covered by **small nodules** w/ **central** **apthous ulceration**
## Footnote
**- Intraepithelial T lymphocytes**
51
What is the most common specific cause of Granulomatous Gastritis in Western populations?
Other causes?
- **Chron** disease **(most common) --\>** noncaseating granulomas
- Sarcoidosis
- Infections (mycobacteria, fungi, CMV, and *H. pylori)*
52
What are the risk factors for PUD (10 of them from table)?
- *H.pylori* infection
- Cigarette use (synergizes w/ *H.pylori* )
- COPD
- Illicit drugs
- NSAIDs
- Alcoholic cirrhosis
- Psychological stress
- Endocrine cell hyperplasia
- ZE syndrome
- Viral infection (CMV, herpes simplex)
53
Nearly all peptic ulcers are associated w/ what 3 risk factors?
1) *H. pylori*
2) NSAIDs
3) Cigarette smoking
54
Most common form of PUD occurs where in stomach and is associated with what?
Levels of what will be increased and decreased?
- Gastric **antrum** or **duodenum** as result of **chronic *H. pylori-induced antral gastritis***
- **Increased gastric acid** secretion
- **Decreased duodenal HCO3-** secretion
55
A new group of duodenal PUD patients \>60 yo have emerged recently as a result of what?
Presence of what can increase risk?
- Increased **NSAID** use
- Especially when low-dose aspirin (for CV benefit) is **combined** w/ other NSAIDs
- Facilitated if **concurrent *H. pylori* infection** is also present
56
How can cigarette use and CV disease contribute to PUD?
Reduced mucosal blood flow, oxygenation, and healing
57
Where in the duodenum are peptic ulcers most commonly seen?
Involve what part of the wall?
- **Prox. duodenum** near the **pyloric valve**
- **Anterior** duodenal wall
58
Grossly how does the classic peptic ulcer appear?
**Sharply punched-out defect** w/ hemorrhage and fibrosis
\*Is virtually diagnostic
59
Perforation of a peptic ulcer into the peritoneal cavity is considered what?
How may this be detected clinically?
- Surgical emergency
- Detection of **free air under the diaphragm** on upright radiographs of abomen
60
What is a possible complication due to the scarred vessel walls and thickening of vessels seen in PUD?
Life-threatening **hemorrhage**
61
What is the most frequent complication associated with PUD?
Bleeding
\*May be **first** indication of an ulcer
62
Which complication of PUD is most often associated w/ chronic ulcers and more often assoicated w/ pyloric channel ulcers?
Causes what symptoms?
- **Obstruction 2° to edema or scarring**
- Incapacitating, crampy abdominal pain
63
Which complication associated w/ PUD accounts for 2/3 of ulcer deaths?
Perforations
64
What are the major clinical signs and symptoms of PUD?
- **Epigastric burning** or **aching pain**
- Pain is worse **1-3 hrs** **after meal** and **worse at night**; relieved by **alkali foods**
65
How does a meal affect the experience of pain in someone with a gastric ulcer vs. duodenal ulcer?
- **Gastric** --\> pain = worse 1-3 hrs after meal
- **Duodenal** --\> pain **improves** w/ meal
66
Some patients with PUD may present with what complications others than epigastric burning or aching pain (i.e., more serious complications)?
- Iron deficiency anemia
- Hemorrhage
- Perforation
67
PUD that is penetrating may cause pain to be referred where and can be misinterpreted as?
- Referred to the back
- LUQ
- Chest
\*Misinterpreted as **cardiac** in origin
68
What are the current mainstays of treatment for PUD?
- *H. pylori* eradication
- PPI's to neutralize gastric acid
\*Important to withdraw agents such as NSAIDs and selective COX-2 inhibitors
69
Which glands are affected in autoimmune gastritis?
Gastric body **oxyntic glands**
70
Risk of gastric adenocarcinoma is greatest in what type of gastritis?
Autoimmune gastritis (chronic)
71
Oxyntic atrophy may be associated with intestinal metaplasia, recognized by the presence of \_\_\_\_\_\_\_\_\_\_\_\_\_.
Goblet cells
72
How can the distinction between dysplasia and regenerative epithelial changes induced by active inflammation be distinguished morphologically?
- **Reactive epithelial cells** mature as they reach mucosal surface
- **Dysplastic** lesions remain cytologically immature
73
Menetrier disease is associated with excess?
Characterized by?
Anatomicaly where is it seen?
- Excess secretion of **TGF-α**
- Diffuse **hyperplasia** of the **foveolar** **mucus cells** of the **BODY** and **FUNDUS**
- **Hypo**-proteinemia
74
Morphologically what is the most characteristic findings in Menetrier Disease?
- **Hyperplasia of foveolar mucus cells**
- **Glands** = **elongated** w/ a **corkscrew-like appearance**
75
Which disease is this characteristic of?
Menetrier disease
\*Markerd **hypertrophy** of **rugal folds**
76
2° symptoms of Menetrier disease (3 most common)?
- Weight loss
- Diarrhea
- Peripheral edema
77
When does Menetrier disease typically affect children?
Often following a **respiratory infection**
78
Are Zollinger-Ellison syndrome and Menentrier Disease associated w/ increased risk for adenocarcinoma?
**Menetrier disease ONLY**
79
What is the most common gastric location of Zollinger-Ellison syndrome?
Predominant cell type?
Inflammatory infiltrate?
- **Fundus** of stomach
- **Parietal** \> mucous, endocrine = predominant cellt types
- **Neutrophils**
80
Zollinger-Ellison syndrome is caused by what?
Patients often present how?
- **Gastrin**-secreting tumor of the **pancreas** or **small intestine**
- Pt present w/ **duodenal ulcers** and **chronic diarrhea**
81
What is the **most remarkable feature** found in the stomach of someone with Zollinger-Ellison syndrome?
**2x thickness** of **oxyntic mucosa** due to **5x** the **# of parietal cells**
82
How fast do gastrinomas grow and are they typically benign or malignant?
- **Slow growing**
- **60-90%** are **malignant**
83
MEN-1 is associated with what tumor of the GI?
Gastrinomas ---\> Zollinger-Ellison syndrome
84
High levels of gastrin associated w/ ZE syndrome induces what changes?
- **Hyperplasia** of **mucous neck cells**
- **Mucin hyperproduction**
- Proliferation of **endocrine cells**
85
The major type/most common type of gastric polyps are of what type?
Inflammatory and Hyperplastic polyps
86
Inflammatory/hyperplastic polyps are most common in what age group?
Develop in association with what underlying disorder?
- **50-60 y/o**
- Develop in association w/ **chronic gastritis**
87
The risk of dysplasia associated with inflammatory/hyperplastic polyps is correlates with what?
Which polyps should be resected for further examination?
**Size**, polyps **larger than 1.5 cm** should be resected
88
Microscopically how does inflammatory/hyperplastic polyps look?
Irregular, cystically dilated, and **elongated foveolar glands** (**"cork-screw shaped**)
89
Fundic Gland Polyps occur in what 2 ways?
Which is associated with a risk of cancer?
1) Sporadically
2) Pts w/ **familial adenomatous polyposis (FAP) --\> dysplasia --\> adenomcarcinoma**
90
Why has the prevalence of Fundic Gland Polyps increased markedly in recent years?
- Use of PPI's
- Lead to increased gastrin --\> oxyntic gland growth
91
How do Fundic gland polyps appear mophologically?
What are the dominant cell types seen?
**Cystically** dilated glands lined by **parietal, chief**, and **foveolar cells**
92
What are 3 risk factors for Gastric Adenomas?
1) Chronic gastritis
2) Atrophy
3) Intestinal metaplasia
93
Which age group and sex is most commonly affected by Gastric Adenomas?
- Pts **50-60 yo**
- **Males 3x** more often
94
Which size lesion in Gastric Adenomas is associated w/ increased risk for adenocarcinoma?
**\>2 cm**
95
What are the morphological characteristics of Gastric Adenomas?
Intestinal-type **columnar epithelium** w/ **varying degrees of dysplasia**
96
Where are Gastric Adenomas most commonly found?
Antrum
97
Gastric adenomas are ____________ neoplastic lesions
Pre-malignant
98
Which 2 gastric polyp types are associated with familial adenomatous polyposis (FAP)?
1) Fundic gland polyp
2) Gastric Adenoma
99
What is the most common malignancy of the stomach?
Gastric Adenocarcinoma
100
What are the late sx's associated with Gastric Adenocarcinom, which usually prompt further diagnostic evaluation?
- Weight loss
- Anorexia
- **Early satiety (primarily in DIFFUSE cancers)**
- Anemia
- Hemorrhage
101
Which countries have a 20-fold higher incidence of gastric adenocarcinomas?
- Japan
- Chile
- Costa Rica
- Eastern Europe
\*More common in **low SES** groups
102
Where are the most common sites of metastasis for Gastric Adenocarcinoma?
- Supraclavicular sentinel LN (**Virchow node**)
- Periumbilical LNs (**Sister Mary Joseph nodule**)
- Left axillary LN (**Irish node**)
- Ovary (**Krukenberg tumor**)
- Recto-uterine pouch (**of Douglas**)
103
What are 3 recognizable precursor lesions/risk factors for Gastric Adenocarcinoma?
1) Gastric dysplasia
2) Adenomas
3) *H. pylori* infection
104
The cause of overall reduction in gastric cancer is most closely linked to what?
Other factors?
Decreases in *H. pylori* prevalence
105
Prevalence of which type of gastric cancer is actually on the rise?
Cancer of the gastric **cardia**
106
Familial gastric cancer is strongly associated with what genetic mutation?
This gene encodes what?
- Germline loss-of-function mutations in ***CDH1***
* -* Encodes **E-cadherin**
107
Loss of which protein is a key step in the development of **diffuse** gastric cancer?
E-cadherin
108
Individuals with what gene mutation related to breast cancer are at an increased risk for developing **diffuse** **gastric cancer?**
***BRCA2***
109
Sporadic **intestinal-type** gastric cancers are strongly associated w/ mutations that result in increased signaling of which pathway?
Which loss of function and gain of function mutations seen in this type of cancer can lead to increased signaling via this pathway?
- ***WNT pathway***
- **G.O.F** in gene encoding **β-catenin**
- **L.O.F.** or silencing of ***APC,*** **TGFβ, *BAX****, or **CDKN2A***
110
In the context of *H. pylori* infection genetic variants of which immune response genes are associated w/ an elevated risk of gastric cancer?
- IL-1β
- TNF
- IL-10
- IL-8
- TLR4
111
Persons with **FAP** and what **associated germline mutations** have an increased risk for the **intestinal-type gastric cancer**, especially in high-risk areas such as Japan?
***APC***
112
Gastric tumors with an intestinal morphology tend to form ________ tumors, and are composed of ________ structures
Gastric tumors with an intestinal morphology tend to form **bulky** tumors, and are composed of **glandular** structures
\***Diffuse-type** does NOT form glands
113
Gastric cancers with a **diffuse infiltrative growth** pattern are more often composed of what type of cells?
**Singlet-ring cells =** large mucin vacuoles which expand cytoplasm and push nucleus to periphery
114
Infiltrative diffuse gastric cancers often evoke which reaction that stiffens the gastric wall?
Why is this important as a diagnostic feature?
- **Desmoplastic** reaction
- Stiffening of the gastric wall --\> **early satiety** --\> **VALUABLE diagnostic clue**
115
When there are large areas of infiltration with a gastric cancer, diffuse rugal flattening and a rigid, thickened wall may impart what type of appearance?
Known as?
- **Leather bottle** appearance
- **Linitis plastica**
116
Is this PUD or Gastric cancer; how can you tell?
- Gastric adenocarcinoma (**intestinal-type**)
- Elevated mass w/ **heaped up border** and **central ulceration**
117
How does Intestinal-type gastric cancer vs. diffuse gastric cancer differ in where they predominate?
Precursor lesions associated with each type?
- **Intestinal-type** predominates in **high-risk** areas, while incidence of **diffuse-type** is relatively uniform across countries
- **Intestinal-type** develops from pre-cursor lesions including **flat dysplasia** and **adenomas.**
- **NO known precursor lesions** for the **diffuse type**
118
When possible, what is the preferred treatment for gastric adenocarcinoma and if successful what is the prognosis?
- Surgical resection
- 5-year survival of 90% even w/ metastases
119
What is the overall prognosis of gastric adenocarcinoma in the United States?
**Poor**; **\<30%** due to most being caught at **advanced stage**
120
In allogenic HSC and organ transplant receipients, the bowel is the most frequent site for?
Due to what factor of the procedure?
- **EBV+ B-cell lymphoproliferations**
- **Deficits in T-cell function** caused by oral immunosuppressive agents (i.e., cyclosporine)
121
Which type of gastritis is associated with the induction of MALT in the stomach?
Caused by what?
- Chronic gastritis
- *H. pylori* infection
122
How effective is *H. pylori* eradication in the treatment of patients with stomach MALToma?
The presence of which translocation/pathway of activation represents an exception to this?
- Durable remission w/ **low rates** of **recurrence**
- Tumors with translocations involving ***MLT*** or ***BCL10*** causing **NF-kB activation** will **NOT** respond to *H. pylori* eradication
123
Which 3 translocations are associated w/ gastric MALToma?
Which is most common?
- **t(11;18) = most common**
- t(1;14)
- t(14;18)
124
What does the **t(11;18)** translocation bring together in the development of gastric MALToma (i.e., fusion product)?
Joins ***API2*** gene on **cr. 11** w/ the ***MLT*** gene on **cr. 18**
## Footnote
**\**API2-MLT fusion***
125
Which proteins are increased with the t(14;18) and t(1;14) translocations associated w/ gastric MALToma?
- **t(14;18)** --\> **MALT1**
- **t(1;14)** --\> **BCL-10**
126
All three translocations associated with gastric MALToma have the same net effect, which is what?
Activation of NF-kB --\> **B-cell growth** and **survival**
127
Histologically, gastric MALTomas take the form of what and where?
Dense lymphocytic infiltrate in the **lamina propria**
128
Which B-cell markers are expressed by MALTomas and which is only present in 25% of cases but can be a useful diagnostic feature?
- **CD19** and **CD20**
- **CD43 -** 25% of cases
129
Carcinoid tumors of the GI tract arise from where and are now called what?
- **Endocrine** system components
- ***Well-differentiated neuroendocrine tumors***
130
Where in the GI are the majority (40%) of carcinoid tumors found?
Mean patient age of onset?
- **Jejunum** and **Ileum** (throughout)
- **65 yo**
**\*MOST COMMON malignancy in Small Intestine!**
131
What is the major secretory products of carcinoid tumors of the jejunum and ileum?
**Serotonin**
Substance P
Polypeptide YY
132
Which location in the GI is affected by the **most aggressive** carcinoid tumor?
Jejunum and Ileum (most common location of these tumors)
133
Gastric carcinoid tumors are associated with what 4 diseases/syndromes?
Which type of gastritis specifically?
- Endocrine cell hyperplasia
- **Autoimmune** atrophic gastritis
- **MEN-1**
- **Zollinger-Ellison syndrome**
134
What is the most frequently affected location of the stomach seen in carcinoid tumors?
Secretory products of this type?
- **Body** and **fundus**
- **Histamine** - **Somatostatin** - **Serotonin**
135
Carcinoid tumors may be associated with what clinical syndrome and what are the associated symptoms?
Strongly associated with metastatic disease of which organ?
- **Carcinoid syndrome**
- Cutaneous **flushing, sweating, bronchospasm, colicky abdominal pain**
- **Diarrhea**
- **Right-sided cardiac valvular fibrosis**
\*Strongly associated with **metastatic dz** of the **liver**
136
What happens to the vasoactive substances released by carcinoid tumors confined to the intestine?
Metabolized to inactive forms by **liver**, **"first-pass"** effect
\*Liver contains **monoamine oxidase**
137
What is the prognosis of GI carcinoid tumors arising in **foregut (esophagus, stomach, duodenum prox. to lig. of Treitz)** structures?
Metastasis?
- Metastasis is **RARE**
- Generally cured by resection
138
What is the prognosis of GI carcinoid tumors arising in **midgut (jejunum/ileum)** structures?
Metastasis?
- Tend to be **aggressive**
- Greater depth of invasion, increased size, and **overall worse outcome**
139
What is the prognosis of GI carcinoid tumors arising in **hindgut (appendix, colon, rectum)** structures?
Where in the appendix do these occur and age of onset?
Metastasis?
- Almost **always** BENIGN
- Appendix --\> occur at any age + localize to **tip** + \<2cm + **benign**
- Metastasis is uncommon
140
Carcinoid tumors of the proximal 1/3 of the duodenum secrete what products?
Associated with what diseases/syndromes?
- Gastrin, Somatostatin, CCK
- **ZE** syndrome and **NF-1**
141
Carcinoid tumors of the rectum secrete what products?
Associated symptom?
- Serotonin and Polypeptide YY
- **Abdominal pain** and **weight loss**
142
What is the most common **mesenchymal** tumor of the abdomen and where in the GI do a majority of them occur?
- **GI stromal tumor (GIST)**
- Stomach
143
GI stromal tumors (GIST) are mesenchymal and arise from which cells?
**Interstitial cells of Cajal (ICC)**
144
Although rare, GISTs seen in children are associated with what triad?
Primarily seen in which sex?
- **Carney triad** --\> primarily **young females**
1) GIST
2) Paraganglioma
3) Pulmonary chondroma
145
There is an **increased incidence** of **GIST** seen in persons with which underlying genetic condition?
NF1
146
Majority of GISTs have oncogenic, gain-of-funciton mutations in what?
Although not as common, what is another mutation associated with GISTs that is overrepresented in the stomach?
- Receptor tyrosine kinase: **KIT = majority**
- **PDGFRA** overrepresented in the stomach
147
Genetic mutations causing a loss of what are associated with an increased risk of **GIST** and paraganglioma (**Carney-Stratakis syndrome**)?
**SDH** function (components of mitochondrial succinate dehydrogenase complex)
148
What are the major morphological characteristics of primary gastric GISTs?
Size, histological, and types?
- **Large**, as much as **30 cm**
- Solitary, well-circumscribed, fleshy mass
- **Whorled** appearance
- Can be **spindle cell type** and **epithelioid type**
149
What is the most useful diagnostic marker of GISTs?
Detectable where?
**KIT** which is detectable in **Cajal cells** via immunohistochemical stain
150
Symptoms of GISTs are sometimes related to what?
Half of patients will present with what underlying problem?
How are these tumors typically discovered?
- Sx's due to **mass effect**
- Half present with **anemia** and associated sx's due to **mucosal ulceration**
- Often discovered **incidentally** during **XR, endoscopy,** or **abdominal surgery**
151
Which type of GIST is typically less aggressive and which is typically more?
- **Gastric GISTs** are typically **less**
- **Intestinal GISTs** are typically **more**
152
What are the treatment options for GISTs and how does genetics play a role in tx?
- Complete surgical resection is **primary tx**
- Pt w/ mutation in **KIT** or **PDGFRA** often respond to tyrosine kinase inhibitors --\> **imatinib**
153
Granulomatous Gastritis is a term applied to any gastritis that contains well-formed __________ and aggregates of which immune cell type?
- Well-formed **granulomas**
- Aggregates of **macrophages!**
