Ch. 17: The GI Tract Flashcards
1
Q
fistula
A
connection of two tubes
-happens with trachea and esophagus
2
Q
atresia
A
blind upper and lower esophagus with that little string thing in the middle
3
Q
diaphragmatic hernia
A
abdominal viscera go into thoracic cavityy
-causes pulmonary hypoplasi= incompatible with life
4
Q
omphalocele
A
when closure of abdominal musculature is incomplete and the abdominal viscera herniate into a ventral membranous sac
-gastroschisis is similar but it involves all of the layers
5
Q
ectopia
A
most frequent: ectopic gastric mucosa in upper third of esophagus
6
Q
ectopic pancreatic tissue
A
in esoph or stomach
-may mimic invasive cancer
7
Q
gastric heterotopia
A
small patches of ectopic gastric mucosa in the small bowel or colon
-may present with occult blood loss due to peptic ulceration of adjacent mucosa
8
Q
meckel diverticulum
A
true diverticulum
- outpouching of alimentary tract
- occurs at ILEUM
- failed involution of the vitelline duct
- 2’s
9
Q
pyloric stenosis
A
more common in males
- turner syndrome and trisomy 18
- erythromycin and azithromycin exposure
- present between 3rd and 6th weeks of life NOT RIGHT AWAY
- firm ovoid abdominal mass
- obstructs the gastric outflow tract
10
Q
hirschsprung disease
A
10% with down syndrome
- aganglionic megacolon
- distal instestinal segment that lacks both Meissner submucosal and the Auerbach myenteric plexus
- rectum is always affected
- failure to pass meconium
- bilious vomiting
- acquired version can come from Chagas disease (T. Cruzi)
11
Q
nutcracker esophagus
A
high amplitude contractions at the distal esophagus
-loss of coordination of inner and outer muscle layers
12
Q
diffuse esophageal spasm
A
contraction of the distal esophageal smooth muscle
13
Q
hypertensive lower esophageal sphincter
A
abscence of altered patterns of osphageal contraciton
-achalasia is the same way but WITH perstaltic contractions…achalasia has no peristalsis
14
Q
zenker diverticulum
A
above the upper esophageal sphincter
-regurgitation and halitosis
15
Q
esophageal stenosis
A
atrophy of the uscularis propria
- benign: so they maintain their appetite and wiehgt
- malignant strictures are often associated with weight loss
16
Q
esophageal mucosal webs
A
ledge-like protusions that may cause obstruction
- women older than 40
- iron deficiency anemia, glossitis, cheilosis= plummer vinson sndrome
- **dysphagia of incompletely chewed food
17
Q
plummer-vinson syndrome
A
associated with esophageal webs
-iron deficiency anemia, glossitis, and cheilosis
18
Q
esophageal rings
A
like webs but they’re circumferential
- A rings: squamous mucos
- B rings: in lower esophagus and may hae gastric cardia-type mucosa on their undersurface
19
Q
Achalasia
A
triad of incomplete LES relaxation, increased LES tone, and aperistalsis of the esophagus
- primary: result of distal esophageal inhibitiory neuronal ganglion cell degeneration
- Secondary: from Chagas disease! T. cruzi gets the myenteric plexus
20
Q
Esophagitis
A
- lacerations
- chemical and infectious
- reflux
- eosinophilic
- esophageal varices
- barrett esophagus
- esophageal tumors
- adenorcarcinoma
- SCC
21
Q
Mallory-Weiss tears
A
longitudinal mucosal tears in esophagus
- 2ndard to acute alcohol intoxication
- hematemesis
- healing is rapid and complete
22
Q
Boerhaave syndrome
A
much less common, but more serious
- transmural tearing and rupture of the distal esophagus
- requires surgical intervention
- myocardial infarction
23
Q
odynophagia
A
pain on swallowing
24
Q
pill-induced esophagitis
A
when they ledge and idssolve in the esophagus
25
esophageal infections
uncommon
- herpes simplex virus: punched out ulcers, nuclear viral inclusions*
- CMV: shallower ulcerations: nuclear AND cytoplasmic inclusions within capillary endothelium and stromal cells
- candidiasis is most common fungus: pseudomembranes
26
reflux esophagitis
stratified squamous epithelium to columnar epithelium with glands
- transient lower esophageal sphincter relaxation
- basal zone hyperplasia exceeding 20% of total epithelial thickness
- ppl older than 40
27
eosinophilic esophagitis
large numbers of intraeptihelial eosinophils, particularly superficially
- PPI's don't provide relief
- children in developed countries
28
esophageal varices
portal vein probs
- cirrhotic patients
- alcoholic liver disease
- hepatic schistosomiasis is the second most common cause of varices
- variceal hemorrhage is an emergency
- submucosa of the distal esophagus
29
barret esophagus
complication of chronic GERD
- increased risk of esophageal adenocarcinoma
- most do not develop tumors though
- goblet cells!
- stain bpale blue by H and E stain
- can only be ID'ed through endoscopy and biopsy.... prompted by GERD symptoms
30
esophageal tumors
either adenocarcinoma or SCC
| -the benign ones are mesenchymal and arise within the esophageal wall... leiomyomas being most common
31
adenocarcinoma
- most arise from Barrett esophagus
- H. pylori is decreased risk becuase they cause gastric atrophy... reduced acid secretion and reflux
- metaplasia to dysplasia and invasive carcinoma
- TP53 and CKDN2A abnormalities detected early
- distal 3rd of esophagus
32
squamous cell carcinoma
males 4x more likely than females
- tobacco and alcohol use
- HPV
- middle 3rd of esophagus
- hot beverages too!
33
Gastritis
inflammatory process
| -neutrophils will most likely be present
34
Gastropathy
when inflammatory cells are rare or absent
- surface epithelium is intact, but with goveolar cell hyperplasia... characteristic corkscrew profiles
- NSAID induced gastropathy responds to antacids or PPI's
35
hypertrophic gastropathy
specific group of diseases
| -menetrier disease and Zollinger-Ellison syndrome
36
stress ulcers
common in ppl with shock, sepsis, or sever trauma
37
curling ulcers
proximal duodenum
| -associated with severe burns or trauma.
38
cushing ulcers
gastric, duodenal, and esophageal ulcers
- ppl with intracranial disease
- high incidence of perforation.
39
non-stress-related causes of gastric bleeding?
Dieulafoy lesion and gastric antral vascular ectasia (GAVE)
40
dieulafoy lesion
caused by submucosal A. that does not branch properly within the wall of the stomach
- lesser curvature, near GE junction
- bleeding associated with NSAID use
41
GAVE
longitudinal stripes on endoscopy
| -antral mucosa shows reactive gastropathy with dilated capillaries containing fibrin thrombi
42
Chronic gastritis
infection with H. Pylori
- Autoimmune could happen too
- hematemesis is uncommon
43
H. Pylori Gastritis
present in 90% of people with chronic gastritis affecting the Antrum
- poverty
- antral gastritis
- flagella, rease, adhesins...
- attach onto foveolar cells
- toxin is CagA
- take an ANTRAL biopsy
- intraepithelial neutrophils and subepithelial plasma cells
- treat w. antibiotics and PPI's
44
Autoimmune gastritis
- typically a patchy process
- spares the antrum
- hypergastrinemia
- Vit. B12 deficiency (because parietal cells secrete IF)
- decreased acid production(loss of parietal cells)
- increased GASTRIN
- CD4 T cells against parietal cell components including the H/K ATPase
- autoantibodies to H/K ATPase found, but not pathogenic
- peripheral neuropathy
45
Eosinophilic gastritis
esoinophils in the mucosa and muscularis
46
lymphocytic gastritis
affects entire stomach
- varioliform gastritis
- marked increase in the number of intraeptihelial T-lymphocytes
47
granulomatous gastritis
granulomas
| -western populations: gastric involvement by Crohn disease is the most common specific cause of this
48
Peptic Ulcer Disease
Complication of chronic gastritis
- ulceration affecting the duodenum or stomach (antrum)
- H. pylori, NSAIDs, or cigarettes
- increased gastric acid secretion and decreased duodenal bicarbonate secretion
- most common in proximal duodenum
- ***sharply punched-out defect
- heaped up margins more characteristic of cancers
- perforation into peritoneal cavity is surgical emergency... free air under the diaphragm
- malgnant transformation of peptic ulcers is rare
- watch out for bleeding (life-threatening hemorrhage)
49
Mucosal atrophy and intestinal metaplasia
- loss of parietal cell mass
| - increased risk for gastric adenocarcinoma (greatest in autoimmune gastritis)
50
Gastritis cystica
- trauma induced
- exuberant reactive epithelial proliferation associated with entrapment of epithelial-lined cysts
- may mimic invasive adenocarcinoma
51
Menetrier disease
rare disorder
- excessive secretion of TGF-a
- diffuse hyperplasia of the foveolar epithelium of the body and fundus
- pediatric disease is usually self-limited and often follows a respiratory infection
- enlarged rugae in the BODY and FUNDUS
- *HYPERPLASIA OF FOVEOLAR MUCOUS CELLS
- associated with adenocarcinoma
- hpoproteiniemia, weight loss, diarrhea
- no risk factors
- limited lymphocyte infiltrate
52
Zollinger-Ellison Syndrome
caused by gastrin-secreting tumors
- 2x of oxyntic mucosal thickness due to a five-fold increase in the number of parietal cells
- fundus
- neutrophilic infiltrate
- peptic ulcers
- MEN is a risk factor
- no adenocarcinoma.... but 60-90% are malignant so watch out
53
Inflammatory and hyperplastic polyps
most frequent kind
- H. pylori
- risk of dysplasia correlates with size
- larger than 1.5 cm.... resect it and examin histologically
54
fundic gland polyps
FAP
- PPI's are a problem.... inhibit acid production... increased gastrin secretion.... oxyntic gland growth
- gastric body and fundus
- FAP associated can be cancerous (adenocarcinoma)
- sporadic fundic gland polyps carry no cancer risk
55
gastric adenoma
Antrum>body
- similar symptoms to chronic gastritis
- frequent association with adenocarcinoma*
- almost alway occur ona background of chronic gastritis with atrophy and intestinal metalasia
56
gastric adenocarcinoma
_the most common malignancy of the stomach
- intestinal (bulky masses) vs. diffuse type (signet ring cells)
- Japan, Chile, Costa Rica, Eastern Europe
- left axillary lymph node is the irish node
- loss of CDH1 gene (E-cadherin) in familial type
- Loss of E-cadherin is also a key stepin in the development of diffuse gastric cancer
- sporadic type: LOF in APC gene and GOF in B-catenin
- lesser curvature more involved
- depth of invasion and extent of nodal and distant metastases= prognosis
57
lymphoma
happens most commonly in the GI tract... stomach
- MALTOMA
- t11,18 translocation
- constitutive activation of NFkB... b cell growth
- dense lymphocytic infiltrate in the lamina propria
- express B-cell markers CD19 and CD20
58
carcinoid tumor
well differentiated neuroendocrine tumors
- has been linked to PPI therapy
- Chromogranin A
- most of these happen at the Jejunum and Ileum
- aggressive there
- *carcinoid syndrome only happens when the tumor has gone to the liver to get dumped intothe venous system
59
Gastrointestinal stromal tumor
GIST
- most common mesenchymal tumor of the abdomen
- arise from the interstial cells of Cajal... pacemaker cells
- GOF mutation in the RTK: "KIT"... most useful diagnostic marker
60
Intestinal obstruction
abdominal pain and istention, comiting, and constipation
- hernias
- adhesions
61
Hernias
most frequent cause of intestinal obstruction worldwide
62
Adhesions
like between bowel segments
- internal herniation
- most common cause of intestinal obstruction in the US
63
Volvulus
- twisted around
| - rare
64
intussusception
proximal part telscopes into the immediately distal segment
- most common cuase of intestinal obstruction in chidren younger than 2 y/o
- air enema will fix kids, surgery for adults
65
Ischemic Bowel disease
vascular compromise...hypoxic injury
- MOST COMMON SITE IS THE SPLENIC FLEXURE!
- most common in older than 70 (colon)
- surface epithelial atrophy with normal or bigger crypts is morphologic signature of ischemic intestinal disease*
- Bloody diarrhea
- *mortality is doubled in pts with right sided colonic disease (right side is supplied by SMA)
66
angiodysplasia
malformed submucosal and mucosal blood vessels
- cecum or right colon (makes sense because cecum has largest diameter.... greatest wall tension
- after 60s
67
malabsorption
hallmark is steatorrhea
-results from one of 4 things: Intraluminal digestion, terminal digestion, transepithelial transport, and lymphatic transport
68
diarrhea
increase in stool mass, frequency, or fluidity >200gm per day
69
Cystic fibrosis
diarrhea du to intraluminal digestion problem
| -problem with CFTR thing
70
Celiac disease
Problem with Terminal digestion (TD) and transepithelial transport (TET)
- immune-mediated enteropathy
- gluten problems
- gliadin causes most of the disease
- CD8 expressing NKG2D
- HLA-DQ2 or HLA-DQ8 allele
- end of duodenum or proximal jejunum
- increased number of intraepithelial lymphocytes in the VILLUS is key
- anti TTG will be there
- Dermatitis herpetiformis
71
environmental enteropathy
tropical sprue!
| -we dont know what to do about it
72
Autoimmune enteropathy
X-linked
- young children... diarrhea persistent
- FOXP3 (treg cells
- tx with immunosuppressive drugs
73
abetalipoproteinemia
inability to secrete triglyceride rich lipoproteins
- intracellular lipid accumulation
- presents in infancy
- ***acanthocytic red cells (burr cells) in peripheral blood smears
- mutation in MTP (microsomal triglyceride transfer protein
74
lactase deficiency
Congenital.... auto recessive.. born with it... just give them formula
Acquired: down regulation of lactaste gene expression
-Native americans
75
cholera
comma-shaped, gram-negative bacteria that cause cholera,
- Ganges valley of india and bangladesh
- transmitted by contaminated drinking water
- noninvasive, remain in intestinal lumen
- Cholera toxin is encoded by a virulence phage
- binds CFTR and opens it... osmotic driving force... massive diarrhea (the A subunit causes it)
- rice water diarrhea
76
Campylobacter enterocolitis
- traveler's diarrhea
- bloody diarrhea
- can result in reactive arthritis in patients with HLA-B27
- Erythema nodosum
- Guillain-Barre syndrome (flaccid paralysis caused by immuno mediated inflammation of peripheral nerves)
- comma shaped FLAGELLATED, gram negative in stool culture
- crypt architecture is preserved
- influenza-like prodrome
77
Guillain-Barre syndrome
flaccid paralysis cause by immunologically mediate inflammation of peripheral nerves... not HLA linked
78
shigellosis
- gram negative, unencapsulated, nonmotile, facultative anaerobes
- bloody diarrhea
- fecal-oral route or contaminated water
- resistant to harsh acidic stomach
- proliferate intracellularly
- carry virulence plasmids
- LEFT COLON
- M cells in dome epithelium over the peyer patches
- self limited disease: 1 wk of diarrhea, fever, and abdominal pain
- requires stool culture
- you just have to SHIT it out... antidiarrheal won't help... get rid of it
79
salmonella
S. typhi or nontyphoid
- type 3 secretion
- again, it's best to just shit it out
80
typhoid fever
S. Typhi
- but travellers usually get S. paratyphi because they have been vaccinated against typhi
- Gallbladder colonization... gallstones and chronic carrier state
- invade M cells... then go to lymphatics or blood
- terminal ileum... plateau-like elevations
- spleen is enlarged and soft
- parenchymal necrosis in which hepatocytes are replaces by macrophage aggregates.... TYPHOID NODULES
- give Abx!
- Rose spots on chest and abdomen
- pts with sickle cell disease susceptible to salmonella osteomyelitis
81
Yersinia
pumonic and bubonic plague
- pork, raw milk, water
- winter
- Y. enterocolitica more common
- invade M cells, have adhesins that bind to host B1 integrins
- *iron enhances virulence and stimulates systemic dissemination
- ileum, appendix, and RIGHT COLON
82
E. coli
gram negative bacilli in healthy GI tract
| -ETEC, EPEC, EHEC, EIEC, EAEC
83
ETEC
```
Enterotoxogenic E. Coli
-travelers diarrhea
-LT and ST toxin
-LT is like cholera, activates AC... increased cAMP
-
```
84
EPEC
endemic diarrhea
- attaching and effacing A/E lesions
- Type 3 secretion like shigella... infects bacterial effector ptns into epithelial cytoplasm
85
EHEC
O157:H7 (more common) or non...
- cows are natural reservoir
- shiga-like toxins
- HUS is a big concern
- so DONT treat with Abx because that will result in increase shiga like toxins... enhancing the risk for hemolytic uremic syndrome
86
EIEC
no toxins
- invade epithelial cells
- acute self-limited colitis
* EAEC has adherence fibmriae, nonbloddy diarrhea, only visible by electron microscopy, minimal histologic damage
87
Pseudomembranous colitis
- C. difficile
- antibiotic associated colitis
- pseudomembranes
- lamina propria has dense infiltrate of neutophils and occasional fibrin thrombi within capillaries
- superficially damaged crypts... volcano... it erupts... pseudomembrane!
- hospitals
- ptn loss... hypoalbuminemia
- look for C dif toxin rather than culture
88
Whipple disease
* *the only malabsorptive thing caused by defective lymphocytic transport!**
- gram positive actinomycete: Tropheryma whippelii
- organism laden macrophages in mesenteric lymph nodes.... lymphatic obstruction
- foamy macs... like whipped cream
- acid fast stain to rule out mycobacteria
* presents with triad of diarrhea, weight loss, and arthlagia
89
Viral Gastroenteritis
- Norovirus: developed countries and IC pts, single stranded RNA genome
- Rotavirus: encapsulated segmented 2x stranded RNA genome... severe childhood diarrhea, destroys mature enterocytes
- Adenovirus: pediatric diarrhea and IC pts, symptoms resolve within 10 days
90
Ascaris
the one with the goofy life cycle
- ingested eggs, larve get into blood and go to lungs... grow in alveoli, coughed up and swallowed... mature into adult worms
- induce eosinophil -rich inflammatory reaction
- diagnosis is made by eggs in stool samples
91
strongyloides
- in ground soil
- can penetrate unbroken skin
- hatch in intestine and penetrate mucosa.. autoinfection... infection for life
- peripheral eosinophilia
92
necator duodenale
hookworms
- larval penetration through skin
- develop in lungs
- swallowed
- worms attach to mucosa, suck blood, and reproduce
- iron deficiency anemia
- diagnosis can be made by detection of eggs in fecal smears
93
enterobius vermicularis
pinworms
- rarely causes illness
- perirectal mucosa
- itchy butt
- tape!
94
trichuris trichiura
Whipworm
- young children
- usually fine
- heavy infections can cause bloody diarrhea and rectal prolapse
- like pin worms, doesn't penetrate mucosa
95
schistosomiasis
trapping of eggs with in the mucosa nad submucosa
- granulomatous immune reaction
- can cause bleeding or obstruction
- adult worms residing in mesenteric veins
96
intestinal cestodes
Fish and pork tapeworms
| -B12 deficiency and megaloblastic anemia
97
entamoeba histolytica
PROTOZOAN!
- India, mexico, colombia
- chitin wall
- cecum and ascending colon most often
- flask shaped ulcer
98
Giardia lamblia
resistant to chlorine
- flagellated protozoans
- 2 nuclei
- NO invasion
- villous blunting
- immunofluorescent cysts in stool samples
99
Cryptosporidium
* Chronic diarrhea in AIDS patients
- oocyte is ingested, releases sporozoites
- enterocyte engulfs the parasite... settles in an endocytic vacuole within the microvilli
- sodium malabsorption, chloride secretion, increased tight junction permeability
- non-bloody, watery diarrhea!
- Look for OOCYSTS IN THE STOOL
100
Irritable bowel syndrome
Characterized by chronic, relapsin abdominal pain, bloating, and changes in bowel habits
- fecal transplantation can work
- 20-40 y/o
- females
101
Inflammatory bowel disease
Ulcerative Colitis and Crohn disease
102
Ulcerative colitis
- limited to colon and rectum and extends only into the mucosa and submucosa
- toxic megacolon
- malignant potential
- pseudopolyps (mucosal bridges between them) and thin walls
- broad based ulcers
- no granulomas
- bloody diarrhea with stingy mucoid material
- pANCA
103
Crohn's disease
-may involve any area of the GI tract and is typically transmural
-most commonly at ileum
-NOD2
NFkB pathway
-skip lesions
-stricture
-knife like lesions
-*perianal fistula
-recurs after surgery
-TH1 and 17(from IL 23)
-creeping fat
-cobblestoning
-crypt abscesses
-Noncaseating granulomas
-bloody diarrhea
-malabsorbtion of B12 and bile salts
-antibodies to saccharomyces cerevisiae
104
Sigmoid diverticular disease
- not invested by all three layers of the coonic wall
- flask-like outpouchings
- hypertrophy of the circular layer of muscularis propria
- there's a shit ton of diverticula
- sensation of never being able to completely empty the rectum
- often resolves spontaneously
105
Hyperplastic polyps
* must rule out sessile serrated adenoma because they look the same*
- these things are benign though... above is malignant
- Left colon
106
inflammatory polyps
-rectal bleeding, mucus discharge, and inflammatory lesion of the anterior rectal wall
107
hamartomatous polyps
occur sporadically or as components of various genetically determined or acquired syndromes
- Juvenile polyps
- Peutz-Jehgers
108
Juvenile polyps
younger than 5 yrs
- rectal bleeding
- solitary if sporadic
- lots if auto dominant syndrome juvenile polyposis
- SMAD4 mutation
109
Peutz-Jeghers Syndrome
rare auto dominant syndrom
- 11 yrs old
- multiple GI hamartomatous polyps and mucocutaneous hyperpigmentation
- increased risk of several malignancies
- STK11 mutation
110
Neoplastic polyps
most common are colonic adenomas
- majority of adenomas do not progress to become adenocarcinomas
- sessile serrated adenomas are in the right colon (hyperplastic polyps are in the left colon)
* **SIZE MATTERS IN THE COLON*** more malignant-precursors to the majority of colorectal adenocarcinomas
111
Adenomatous Polyposis
FAP: numerous colorectal adenomas as teenagers
- APC gene
- at least 100 polyps
* *colorectal adenocarcinoma develops in 100% of untreated FAP patients
- hypertrophy of retinal pigment epithelium
- MYH lost as well
112
Hereditary Non-Polyposis Colorectal cancer
- Lynch syndrome
- caused by inherited mutations in genes that encode proteins responsible for the detection, excision, and repair of errors that occur during DNA replication (MSH2 or MLH1
- Right sided
113
Adenocarcinoma
the most common malignancy of the GI tract and is a major cause of morbidity and mortality worldwide
- small intestine is an uncommon site for benign and malignant tumors
- aspirin and NSAIDs hav e aprotective effect... inhibiting COX 2 solves probems
- APC to B-catenin to KRAS to TP53 to telomerase (the sequence)
- exophytic masses
- distal colon... napkin ring lesions
- abundant mucin=poor prognosis
- fatigue and weakness due to iron deficiency anemia
* the two most important prognostic factors are depth of invasion and the presence of lymph node metastases
- liver is most common metastatic site b/c of portal drainage of the colon
114
Tumors of the Anal Canal
- pure SCC of anal canal is associated with HPV infection
- basaloid
- upper zone is lined by columnar rectal epithelium
- middle third has transitional eptihelium
- lower third has stratified squamous epithelium
115
Hemorrhoids
anal varices.... they'll be fine
- they relieve venous hypertension
- below anorectal line= external hemorrhoids
- above= internal hemorrhoids
116
Acute Appendicitis
diagnosis of this requires neutrophilic infiltration of the muscularis propria
- RLQ pain
- McBurney sign
117
Tumors of the Appendix
-most common is carcinoid tumor... it's fucking yellow
| -
118
Sclerosing retroperitonitis
Ormond disease= dense fibrosis that may extend to involve the mesentery
-IGg4 related
119
Tumors of the peritoneal cavity
- mesothelioma
- desmoplastic small round cell tumor
- t11,22
- fusion gene of EWS and WT1 genes
