Stomach 2 Flashcards
Hereditary diffuse gastric cancer is an inherited form of gastric CA, caused by what mutation?
E-cadherin mutation
***80% of these pts will develop gastric CA
Li Fraumeni syndrome is an AD syndrome caused by mutation what gene?
p53
**have risk of many malignancies, including gastric Ca
Hereditary non-polyposis colorectal cancer is AKA?
lynch syndrome
Lynch syndrome is a mutation in what?
assc w/ microsatellite instability
**also assc w/ increased risk of ovarian + gastric Ca
What is a micro-satellite?
lengths of DNA where 1 to 5 nucleotides motifs are repeated several times
What are some genes over-expressed in gastric Ca?
c-met
k-sam
c-erbB2
Pts with pernicious anemia are at increased risk of gastric Ca, what’s the defining feature of this dx?
achlorhydria
chief and parietal cells are destroyed by an autoimmune response
MOA of PPIs?
block H-K pump within the parietal cell
block all acid secretion in the stomach
***as a result pts develop hyper-gastrinemia
Few classification systems used to characterize gastric Ca?
Bormann classification–> uses macroscopic appearance, V types
Lauren classification–> separates gastric Ca into intestinal vs. diffuse type
What are some features of intestinal type gastric Ca?
arises in setting of a pre-cancerous condition; like gastric atrophy and intestinal metaplasia
M>W
incidence increases with age
mets via hematogenous spread
environmental causes involved
What are some features of diffuse type gastric Ca?
poorly differentiated, lacks glands
has tiny clusters of signet ring cells
W>M
younger age group affected
assc. w/blood type A
Diffuse type gastric Ca associated with what blood type?
type A
Better prognosis with intestinal or diffuse type gastric Ca?
intestinal type gastric Ca
Supraclavicular mets of gastric Ca called what?
Virchow’s nodes
What are Virchow’s nodes?
gastric Ca that has mets to supraclavicular nodes
What is a Sister Mary Joseph node?
gastric Ca that has mets to peri-umbilical area
Gastric Ca drop mets to ovaries called what?
Krukenberg tumors
Peritoneal gastric Ca mets felt on rectal exam called what?
Bloomer’s shelf
Most widely used staging system for gastric Ca?
TNM
In the TNM staging system for gastric Ca, how many nodes needs to be evaluated?
15
What’s the number of nodes that need to be evaluated in gastric Ca?
15
For gastric cancers of distal stomach, including the body and antrum, what operation do we perform?
distal gastrectomy
*distal margin should be proximal duodenum
frozen section should be performed prior to reconstruction
can do Bilroth I vs II
When performing gastrectomies for gastric Ca, how wide of a margin do we want?
at least 6 cm
studies have shown tumor spread as far as 5 cm
What surgery do we perform for proximal gastric Ca?
total gastrectomy w/Roux-en-y w/esophagojejunostomy
When do we perform endoscopic resection of early gastric Ca?
tumor is limited to the mucosa
there is NO lymphovascular invasion
tumor is smaller than 2 cm
there are no ulcers
Most recurrences of gastric cancer occur within what time frame?
3 yrs
Where does gastric Ca tend to spread to?
liver, lung, bone
MOst common site of lymphomas in the GI system>
stomach
Where do we see lymphomas most commonly in the GI system?
stomach
Share some facts about gastric lymphomas:
occur in older pts (6-7th decade)
M>F
usually occur in antrum
50% of pts will present with anemia
M0st common gastric lymphoma?
diffuse large B cell lymphoma (55%)
Most common gastric lymphomas?
diffuse large B cell (55%)
gastric MALT lymphoma (40%)
Burkitt’s lymphoma (3%)
mantle cell and follicular lymphoma (1%)
Risk factors for development of diffuse large B cell lymphoma??
h. pylori
immunodeficiencies
Burkitt’s lymphoma of stomach associated with what?
Epstein-barr virus
This type of gastric lymphoma is very aggressive, tends to affect younger pts, usually found in cardia of stomach;
Burkitt’s lymphoma
Tx for gastric lymphoma?
surgery controversial
most treated w/chemotherapy alone
Most common chemotherapy regimen for gastric lymphoma is?
CHOP
cyclophosphamide
doxorubicin
vincristine
prednisone
When is surgery for gastric lymphoma performed?
pts w/limited gastric disease
pts w/recurrence of treatment failure
pts w/complications like bleeding, obstruction, perforation
Gastric MALT lymphoma is usually preceded by what?
h-pylori associated gastritis
With this type of gastric lymphoma we see H. pylori involvement and increased NK-B activity;
gastric MALT lymphoma
Tx for gastric MALT lymphomas?
usually tx for h.pylori showed remission in 75% of pts
These gastric tumors derived from interstitial cells of Cajal:
GISTs
Where do we GISTs come from?
originate from interstitial cells of Cajal, pacemaker intestinal cells
Where do we commonly find GISts?
stomach
small intestine
colon
GISTs stain for what CD?
CD117
CD 34
C-kit (CD 117) proto-oncogene associated with what cancer?
GIST
What CD do GISTs express?
90% c-kit proto-oncogene for CD 117
80% for CD 34
Mainstay of tx for GISTs?
complete surgical excision
Demographics of GISTs?
usually pts >50
equal m/f ratio
**Mostly develop de novo
How do pts with GISTs present?
bleeding, abdominal pain, discomfort
Why is long term follow up requires for GISTs?
recurrence can occur as late as 20 yrs
What are the most important risk factors for determining if a GIST is malignant?
tumor size >10 cm
>5 mitoses HPF
What is GLEEVEC?
imatinib
used as adjuvant therapy for GISTs
MOA of imatinib?
tyrosine kinase inhibitor
What drug do we use for GISTs?
imatinib–> tyrosine kinase inhibitor
Most common locations for carcinoid tumors?
small intestine
appendix
rectum
rarely stomach
What is Menetriere’s disease?
rare acquired pre-malignant disease characerized by massive gastric folds in the body and fundus of stomach
mucosa has a cobblestone or cerebriform appearance
Menetriere’s dx is associated with what metabolic dernagements?
protein loss from stomach
excessive mucus production
achlorhydria
What causes Menetriere’s dx?
cause unknown
assc. w/cytmegalovirus in kids and h.pylori in adults
Tx for Menetriere’s dx?
acid suppression
ocreotide
h. pylori eradication
total gastrectomy for pts who have continued protein loss despite medical therapy
This is related to forceful vomiting and retching, that results in disruption of gastric mucosa on the lesser curve at GE junction;
mallory weiss tear
Overall mortality rate for Mallory Weiss tears?
3-4%
highest in alcoholic pts with portal htn
How to manage a Mallory Weiss tear surgically?
most pts w/bleeding can be managed endoscopically
surgery is rare; usually done via anterior gastrotomy, bleeding site is oversewn with 2-0 silk sutures
What is a DIeulafoy gastric lesion?
abnormally large, tortuous artery coursing thru the submucosa
What causes the bleeding seen in Dieulafoy gastric lesions?
you have large tortuous arteries coursing thru the submucosa
pulsations of artery erode the mucosa
artery is then exposed to gastric contents and bleeds
**these lesions usually seen 6-10 cm from GE junction
Classic presentation of a bleeding Dieulafoy lesion?
sudden onset massive painless recurrent hematemesis w/hypotension
What causes gastric varices to develop?
can develop from splenic vein thrombosis causing htn
can develop from portal htn
Gastric volvulus is uncommon and it can occur in two axes:
longitudinal axis; organoaxial (line drawn across lesser curve and greater curve)
vertical axis; mesoaxial (line drawn from GE jxn to pylorus)
Difference between organoaxial and mesoaxial gastric volvulus?
organoaxial occur acutely, assc/ w diaphragmatic defect
mesoaxial volvulus is partial < 180 degrees, its recurrent, not assc. w/diaphragmatic defect
Borchardt’s triad with gastric volvulus?
sudden onset sever abd pain
recurrent retching, minimal vomitus
unable to pass an NG tube
Tx for acute gastric volvulus?
surgical emergency
stomach is reduced and uncoiled thru a trans-abdominal approach
What are bezoars?
collections of non-digestable material
usually vegetable material; phytobezoars
trichobezoars; hair
What is gastrostomy performed for?
alimentation vs decompression
How is gastrostomy performed?
percutaneously (most common)
open
laparoscopic
Open techniques for gastrostomy tube placement?
Stamm method*** most common can be done open vs laparoscopic
Witzel
Janeway method
Complications of gastrostomy?
leakage w/peritonitis
infection
dislodgment
aspiration pneumonia
What causes dumping syndrome?
caused by destruction or bypass of the pyloric sphincter
Early dumping syndrome?
abrupt delivery of a hyperosmolar load into the small bowel due to ablation of pylorus or decreased gastric compliance
15-30 mins after a meal
pt becomes sweaty, weak, light headed, tachycardic
Late dumping syndrome?
2-3 hrs after a meal
usually due to post-prandial hypoglycemia
usually relieved by administration of sugar
Medical management of dumping syndrome?
dietary management somatostatin analogues (ocreotide) (100 micrograms subcutaneously twice daily)
How does ocreotide help in dumping syndrome?
helps ameliorate abnormal hormone pattern
helps restore a fasting motility pattern
Greatest risk factors for stress gastritis?
prolonged ventilation >48 hrs
coagulopathy
What causes late dumping syndrome seen 2-3 hrs after a meal?
rapid dumping of carbs into the intestines
pts become hypoglycemic due to hyperinsulinemia as a result of carb load
What causes symptoms of late dumping syndrome?
carb load enters small intestine–> rapidly absorbed
hyperinsulinemia causes hypoglycemia
hypoglycemia triggers adrenal to make catecholamines–> tachycardia, tremulousness, sweating
Where do we find type 2 gastric ulcers on the Johnson classification?
gastric body + duodenum
**assc w/acid
What is a Cameron’s lesion?
chronic enteric blood loss from linear erosions at the level of the diaphragm within a hiatal hernia
A gastric emptying study is considered abnormal if what
if >60% of radiotracer is present in stomach at 2 hrs
if >10% of radiotracer is present in stomach at 4 hrs
To maintain adequate stomach perfusion which arteries do we need to preserve?
1/4 arteries needs to be intact
celiac artery supplies most of stomach
(4 main arteries are left + right gastric, left + right gastroepiploic)
Left gastro-epipoloic comes off of what artery?
splenic
How do we treat a 3 cm perforated anterior duodenal ulcer?
ulcer too big to close primarily, too much tension
jejunal serosal patch (Thal) should be used , less chance of a leak
to optimize post-op healing, can do temp pyloroplasty with gastrojejunosotomy
GISTs stain for?
c-kit
How do GISTs spread?
hematogenously
**Most commonly spread to liver and peritoneal surfaces
Where do GISTs spread to?
liver
Pts presenting with a Mallory-Weiss tear that resolve, when do you get repeat endoscopy?
not necessary
Gastrinomas AKA?
zollinger-ellison syndrome
How do diagnose a gastrinoma, Zollinger-Ellison syndrome?
secretin stimulation test
measure baseline gastrin levels
2 units/kg of secretin are injected and gastrin levels measured at 5 min intervals for 30 mins
gastrin level > 200 above basal level supports diagnosis
5 year survival of gastric Ca with no neoadjuvant therapy;
I: 88-94%
II: 68-82%
IIIA: 54%, IIIB: 36%, IIIC: 18%
V: 4-5%
When do we see Curling ulcers?
seen after burns >30% TBSA
Benefits of diagnostic laparoscopy vs PET in looking for mets in advanced gastric CA?
PET misses 50% of mets
diagnostic lap is better
