Gastro Flashcards
What is the portal-systemic anastomose seen in an Esophageal Varice?
Left Gastric - Azygos Vein
What is the portal-systemic anastomose seen in
Caput Medusae?
Paraumbillical vein <—> Superficial & Inferior Epigastric Vein
What is the portal-systemic anastomose seen in
Anorectal Varice?
Superior Rectal Vein <—-> Middle & Inferior Rectal Vein
Which landmark will best aid a surgeon in distinguishing between an indirect or direct inguinal hernia?
Inferior Epigastric Vessels
Medial - Direct
Lateral - Indirect
“MD’s LIe”
What are the retroperitoneal structures?
Suprarenal (Adrenal Glands) Esophagus
Aorta + IVC Rectum
Duodenum (besides 1st part)
Pancreas (besides tail)
Ureters
Colon (ascending & descending)
Kidney “SAD PUCKER”
A posterior duodenal ulcer is most likely to penetrate which artery?
gastroduodenal artery
which arteries run along the greater and lesser curvature of the stomach?
lesser curvature: Left & Right Gastric arteries
greater Curvature: Left & Right Gastroepiploic arteries
Which part of the intestine secretes an alkaline substance?
From which gland?
The Small Intestine
Contains Brunners Glands that secrete HCO3/Bicarbonate
The Gastric Fundus gets supplied and drained by which artery and vein? From where do they orginate?
Short Gastric arteries and veins
originate from the splenic artery and vein
In a patient with liver cirrhosis where would we see an increase in pressure?

Point C
Liver cirrhosis results in portal hypertension

A tumor in the transverse (3rd) part of the duodenum can compromise which vessel?
Superior Mesenteric a.
Which lymph node is responsible for drainage of the rectum
a. above the dentate line
b. below the dentate line
a. Internal Illiac LN
b. Superficial Inguinal LN
How does a sliding hiatal hernia occur?
How does it present?
Occurs due to laxity of the phrenoesophageal membrane
Presents with reflux symptoms
(heartburn, regurgitation, chest/epigastric pain)
How/why does a diaphragmatic hernia occur?
How does it present?
Occurs due to a congenital defect in the pleuroperitoneal membrance
Present as:
- Right shift of mediastinal structures due to a hole in the diaphragm allowing the small intestine to come up and push things around
- results in respiratory distress in newborns
Which organ is least susceptible to infarction after occulsion?Why?
Which is most susceptible?
Liver
It has dual blood supply (hepatic artery and portal vein)
Brain is most succeptible
What structures are contained in the Hepatoduodenal Ligament?
What is the name of the maneuver where we clamp down on the ligament?
Portal Triad:
1. Hepatic Artery
2. Portal Vein
3. Common Bile Duct
The Pringle Maneuver
If there is still a bleed in the RUQ following the pringle maneuver, what is the most likely source of this bleed?
IVC or Hepatic Vein
What nerve innervates the rectum below the dentate line?
From where does it originate?
Inferior Rectal Nerve
(a branch of the Pudendal Nerve)
If a hemmorhoid is painful is it external or internal?
External Hemorrhoids
(only external hemorrhoids are painful since they recieve somatic innervation while internal recieves visceral)
Which letter is the esophagus?

Point B
(the esophagus is usually collapsed with no visible lumen on CT images of the chest)
What causes the pain from an appendicitis to go from a dull non localized (visceral) pain to a severe well localized (somatic) pain?
Irritation of the parietal peritoneum
Pneumoperitoneum
- what is it?
- how is it caused?
- how is seen on CXR?
- it is when there is air or gas in the peritoneum
- it is most commonly caused by an anterior duodenal ulcer
- Seen as air under the diaphragm on CXR

What is the most likely diagnosis of a patient who present with a distended abdomen with air in the billiary tree?
Gallstone Ileus
(when a gallstone in the gallbladder enters the duodenum via a fistula and makes its way down to the illeocecal valve where it blocks it)
What does a surgeon look for as something to help him find the appendix/identify the large intestine?
The Teniae Coli
(can be followed to the appendix origin at the base of the cecum)
What are the effect of the following on gastric acid secretion:
- Gastric phase
- Cephalic phase
- Intestinal phase
- increase gastric acid secretion
- increase gastric acid secretion
- decrease gastric acid secretion
A patient with watery oderless stools, hypokalemia, achlorhydria and a lack of gastric acid secretion most likely has what?
VIPoma
What can be used to treat a VIPoma?
Octreotide (somatostatin analog)
What stain is best for screening for malabsorption syndromes?
Sudan Stain
(tests the stool for fat)
Gene mutations that render trypsin insensitve to cleavage inactivation can lead to what?
Pancreatitis
What is the most likely diagnosis of a patient who presents with liver damage and dyspnea without a history of smoking?
alpha1-antitrypsin deficiency
Why would a patient with a removed terminal illeum due to Crohns disease present with easy bruising and impaired coagulation?
Since he will have bile acid malabsorption due to having a resected terminal illeum which with then impair absorption of fat soluble vitamins (A,D,E,K)
Decreased Vit. K results in impaired coagulation
Why do patients recieving total parentral nutrition (TPN) have an increased risk of developing gallstones?
No enteric stimulation so decreased cholecystokinin release and increased billiary stasis
A laparotomy of a patient with acute abdominal pain shows chalky white lesions in the mesentary, fat cell destruction and calcium deposition, what is this patient most likely suffering from?
Acute Pancreatitis
A patient presents with a colonic polyp complaining of a mucoid diarrhea.
What kind of polyp is this?
Does it have malignant potential?

Adenomatous (Villous type) Polyp
Yes it has malignant potential
LLQ pain, fever and leukocytosis are a sign of what?
Diverticulitis
(inflammation of a diverticula)
What patholgy can be seen on this CT?
What is he at increased risk for? (be specific)

Porcelain Gallbladder
(calcified gallbladder)
Adenocarcinoma of the gallbladder
What are the functional liver markers?
What can they help predict?
Billirubin
Albumin
Platelets
Prothrombin Time
They help predict prognosis (outcome) of the disease
Toxic Megacolon
- What is it a complication of?
- How does it present?
- How is diagnosed/visualized?
- Ulcerative Colitis
- abdominal distension, signs of shock, bloody diarrhea
- Normal Chest x-ray
In Peptic (gastric, duodenal) Ulcer disease due to H.Pylori infection, where is the most likely site of bacteria colonization?
Gastric Antrum
What are the effects of the following on the likelihood of developing cholesterol gallstones:
1. increased cholesterol
2. increased bile acids
3. increased phosphatidylcholine
1. increased risk
2. decreased risk
3. decreased risk
An infant presents with fal malabsorption, steatorrhea and failure to thrive.
What is the most likely diagnosis?
Abetalipoproteinemia
(Deficiency of ApoB-48 and ApoB-100)
An infant presents with non-billious projectile vomitting, visible persitaltic waves and and olive shaped mass in his abdomen.
What is the most likely diagnosis?
Pyloric Stenosis
(hypertrophy of stomach pylorus)
A patient has liver cirrhosis and presents with sleep change patterns, altered mental status and asterixis?
What is the most likely diagnosis?
Why does this occur?
Hepatic Encephalopathy
Occurs due the livers inability to metabolize waste products such as ammonia
gets triggered by increased NH3 production+absorption or decreased NH3 removal
What is CREST syndrome?
C: Calcinosis –> calcified skin nodules
R: Raynaud phenomenon –> blue fingers
E: Esohpageal Dismotility (sclerodermal) –> disphagia + acid reflux
S: Sclerodactyl –> thick/tight fingers
T: Telengectasis –> small dilated vessels
H. Pylori is the most common cause of both gastric and duodenal ulcers. What is the 2nd most common cause of:
- Gastric Ulcer
- Duodenal Ulcer
- NSAIDS
- Zollinger-Ellison Syndrome
(Gastrin secreting tumor)
How do duodenal ulcers caused by H.Pylori or ZE Syndrome differ in their:
- Location
- Secretin Test
Location:
H.Pylori: Proximal Duodenum
ZE Syndrome: Distal Duodenum
Secretin Test:
H.Pylori: negative - decreased gastrin
ZE Syndrome: positive - increased gastrin
A patient who has undergone a total gastrectomy will need lifelong supplementation of what? why?
Vitamin B12
Since the gastric parietal cells produce the intrinsic factor that it needs to get absorbed in the illeum
A patient presents with a rash, proximal muscle weakness (cant live arms above head) and dysphagia, what is the most likely diagnosis?
Why does dysphagia occur?
Dermatomyositis
Due to perifascicular atrophy of muscle fibers in the proximal esophagus
Portal Hypertension often results in Splenomegaly. In this case:
- What exactly results in the splenomegaly?
- What area of the spleen gets enlarged?
- Spleen gets congested with RBCs
- The red pulp gets expanded
How can variceal bleeding be acutely mananged?
Somatostatin/Octreotide
(reduce hepatic blood flow)
Hereditary Hemorochromatosis
- Caused by a mutation on what gene?
- What does this mutation result in?
- Classic presentation
- HFE** Gene**
- Increased intestinal iron absorption
- Cirrhosis, Diabetes, bronze skin
(iron gets into liver, pancreas and skin)
What does the following embryonic structures eventually become:
- Ventral Pancreatic Bud
- Dorsal Pancreatic Bud
1.Ventral:
uncinate process & main pancreatic duct
2. Dorsal
body, tail, isthmus and accessory pancreatic duct
BOTH contribute to the head of the pancreas
What is the difference between Portal Vein thrombosis and Budd-Chiari Syndome?
PVT:
- portal vein occulssion
- will cause ascites and varices but NO LIVER CHANGES
Budd-Chiari
- hepatic vein occlusion
- ascites, varices and CONGESTIVE LIVER DISEASE
How does Reye Syndrome present on histology?
Steatosis of hepatocytes
What is the cause of duodenal atresia?
What is the cause of jejunal and/or illeal atresia?
Duodenal Atresia:
Failure of recanalization
Jejunal/Ileal Atresia:
Vascular Disruption/Injury
A patient with Mallory-Weiss Syndrome is most likely to have what type of acid-base disturbance?
(exp: respiratory alkalosis)
Metabolic Alkalosis
(due to vomitting out all the acid)
Zenker Diverticulum
- Is it true or false?
- Where does it occur?
- How does it occur?
- False (only mucosa & submucosa)
- At the junction of the esophagus and pharynx
(above the upper esophageal sphincter)
- Esophageal dysmotility due to diminished relaxation of the cricopharyngeal muscles during swallowing increases intraluminal pressure
How does our body absorb and subsequently remove copper?
Absorbed copper is turned into ceruloplasmin
It then gets secreted into bile
It then gets excreted in the stool
How does Acute Viral Hepatitis present on liver biopsy?
Hepatocyte Necrosis —>
cellular swelling
cytoplasmic emptying
monocyte infiltration

White-yellow plaques on the colonic mucosa composed of fibrin and inflammatory cells are most indicative of what?
Clostridium Difficile Infection
In a patient with pancreatitis due to chronic alcohol consumption what are the 2 laboratory findings that can prove alcohol is the cause?
- AST > ALT
- Macrocytosis
(alcohol results in poor nutrition (folate deficiency), liver disease and alcohol toxicity)
Annular Pancreas
- What is it?
- How does it occur?
- Embryologic abnormality where the pancreas encircles the 2nd part of the duodenum
- abnormal migration of the ventral pancreatic bud
A patient presents with no apparent liver disease other episodes of jaundice in times of stress (infection, after a long hike, etc). What is the most likely diagnosis?
Gilbert Syndrome
A patient presenting with postprandial epigastric pain that does not respond to antacids and weight loss due to food aversion is most likely suffering from what?
What is this pathophysiology similar to?
Chronic Mesenteric Ischemia
(atherosclerosis of the Celiac, SMA or IMA)
(Pain is worse after a meal due to increased demand)
Pathophysiology is similar to Angina
In a hypotensive state which parts of the colon would be most suceptible to damage?
Splenic Flexture
(watershed area between SMA and IMA)
Rectosigmoid Junction
(watershed area between the IMA and superior rectal a.)

A patient with right sided abdominal pain and recurrent bouts of bloody diarrhea undergoes a colectomy. The findings are shown in the following image.
What is the likely diagnosis?

Crohns Disease

Which 2 GI pathologies have PAS + stains?
What are the main differences?
1. Whipple Disease
- macrophages loaded with T. Whipelli in SI lamina propria
- presents with diarrhea/steatorrhea
2. alpha1-antitrypsin deficiency
- misfolded protein accumulates in ER of hepatocytes
- presents with liver damage and dyspnea
Why is the PAS stain good for evaluating Whipple Disease?
The PAS stain stains the glycoproteins in the cell wall of the Tropheryma Whiplei bacteria
How does Vitamin E deficiency most commonly present?
Ataxia
Impaired proprioception and vibratory senstation
Muscle Weakness
hemolytic anemia
A patient dies from an upper GI bleed an autopsy of his liver is done and shown in the image below.
What was the cause of his death?

Liver Cirrhosis
(we can see the regenerative nodules of the liver)
How does a cirrhotic liver appear?
Bands of fibrosis and many regenerative nodules

What can be given to prevent an adenomatous polyp from mutating into carcinoma?
Aspirin (COX inhibitor)
helps prevent the p53 mutation that results in
adenoma –> carcinoma
From what is the spleen derived?
mesoderm
From what is the GI tract, liver and pancreas derived?
Endoderm
Why do pregnant women often develop GERD?
- High levels of estrogen and progesterone cause LES relaxation
- The uterus can press on the stomach and alter the LES angle
A patient with diabetes that is not being well taken care of presents with postprandial vomitting of recently eaten undigested food and early satiety.
What is the the most likely diagnosis and pathogenesis?
Diagnosis: Diabetic Gastroparesis
Pathogenesis: dysfunction of gastric enteric neurons
(due to chronic hyperglycemia)
A patient has RLQ pain and an inflamed terminal illeum which is removed. A biopsy is done and can be seen in the image below.
What is the most likely diagnosis?
What mediated it?
What can be seen in the image?

Crohn Disease
Th1 mediated
Noncaseating granulomas
An old man is complaining of having bright red blood in his stool. Colonoscopy reveals numerous mucosal outpouchings in the sigmoid colon.
What is the diagnosis?
What would histology of these outpuchings reveal?
Diverticulosis
(many false diverticula of the colon, most commonlt in sigmoid)
A mucosa and submucosa but NO muscularis propria
(since it is a false diverticulum)

The inappropriate activation of which enzyme results in acute pancreatitis?
Trypsinogen
What stimuli is most likely to cause parietal cell proliferation?
When would this be seen?
Gastrin
Zollinger-Ellison Syndrome
(gastrin hypersecretion)
A middle aged women presents with pruritis, antimitichondrial antibody + and has a sister with Sjorgren Syndrome.
What is the most likely diagnosis?
Primary biliary cholangitis
What can delay the progression of hemochromatosis in women?
Physiologic iron loss through menstruation and pregnancy
Cholesterol 7-alpha hydroxylase
- What is used for?
- What drug inhibits it?
- it catalyzes the rate limiting step in the synthesis of bile acids from cholesterol
- Fibrates, increasing the risk of cholesterol gallstones
What test should be used in a patient with an elevated alkaline phosphatase?
y-glutamyl transpeptidase
A woman has been having fecal incontinence since giving birth to her 1st child a year ago.
What is the most likely cause?
Damage of the anal sphincter during delivery
An old man comes in complaining of severe constipation.
Laxatives has not improved his symptoms.
Which nerve is most likely dysfunctions?
Pelvic Splachnic nerve
Annular Pancreas
- What is it?
- What complications can it cause?
1.
Developmental malformation in which the pancreas forms a ring around the duodenum
2.
Can result in duodenal obstruction –> billious vomitting in a newborn
Brown Gallstones
- Caused by what?
- What substance is released that results in the stone?
- Infection
(exp: E.Coli) - Beta-Glucuronidase
Black Gallstones are caused by what?
Chronic Hemolysis
If the cricopharyngeal muscles cannot relax during swallowing what can occur?
Zenker (false) Divierticulum in the Esophagus
(occurs due to increased intraluminal pressure)
D-xylose
- What is it?
- What is it useful?
- type of monosaccharide
2.
Since it is a monosaccharide it does not need pancreatic enzymes to break it down for absorption.
Since its absorptive function independant of pancreatic function it can be used to differentiate between pancreatic vs. mucosal/intestine damage
If a patient has portal hypertension and liver biopsy shows
a. No abnormalities
b. Congestion
In which vein is an occlusion more likely?
(Portal or Hepatic Vein)
a. No abnormalities —> Portal Vein
b. Congestion —> Hepatic Vein (Budd-Chari)
Order of blood flow is Portal Vein –> Liver –> Hepatic vein
Monitoring the serum Carcinoembryonic Antigen (CEA) in a patient with colon cancer is most useful for what?
Monitoring Tumor Recurrence
Portal hypertension can result in splenomegaly since the splenic vein is part of the portal circulation.
What part of the spleen is most likely to be affected?
Red Pulp with be expanded
(due to congestion of blood in spleein)
Colitis Associated Colorectal Carcinoma
In compatison to the sporadic (APC) type is it more likely to:
a. Occur in younger or older patients
b. Have a singular or muliple tumor
c. Have an APC or a p53 mutation first
a. Younger patients
b. Multiple/multifocal tumors
c. p53 mutation occurs before APC mutation
(normally APC–>K-ras–> p53)
- What type of tumor is this?
- Where in the GI tract is it most likely to originate?
- What type of cells is it made up of?

- Carcinoid tumor
- Small intestine, Appendix, rectum
- Neuroendocrine cells
What are the 2 primary sources of Alkaline Phosphatase?
What additional marker can we look for to differentiate between the 2?
Liver/Gallbladder and Bone
gamma-glutamyl transpeptidase since it is not found in bone
What gene mutation is seen in Hemochromatosis?
What does it result in?
HFE gene
Increased intestinal iron absoorption
Necrtotizing Enterocolitis
- What population is it seen in?
- What does it result in?
- How does it present?
- How is it seen on x-ray?
- Premature infants that are fed formula
2. Necrosis of intestinal mucosa which can cause a perforation
3. Abdominal distenstion, vomitting
4. Pneumatosis Intestinalis (free air in abdomen)
(there will be areas of luncency)

What kind of liver tumor is this?
Benign or Malignant?
How common is it?
Should you take a biopsy of it?

CAVERNOUS HEMANGIOMA
Benign
Most common benign liver tumor
NEVER take a biopsy of it, due to risk of hemorrhage
What change occurs to the hepatocytes in Reye Syndrome?
Microvescular Steatosis of Hepatocytes
What problem occurs in Wilson Syndrome?
Defective copper transport due to decreased ceruloplasmin uptake in hepatocytes which leads to impaired biliary excretion of copper
Copper then builds up in the liver and leaks into blood where it can then enter the brain (neurological issues) and the eye (keiser-fleisher rings)
A patient with diabetes has been experiencing several months of watery diarrhea
- Most likely diagnosis
- Why does it occur?
- Diabetic Diarrhea
2. prolonged hyperglycemia can injure the sympathetic and parasympathetic systems resulting in decreased bowel motility and increased secretions
Which vein drains into the liver?
Which vein drains out of the liver?
Portal Vein –> Liver –> Hepatic Vein
What effect does portal vein thrombosis have on the liver?
It doesnt
(portal vein –> Liver –> heptatic vein)
Budd-Chiari Syndrome
- What vein is blocked?
- What does it result in?
- Hepatic Vein
2.
Hepatomegaly and Ascites
(Portal Vein –> Liver –> Hepatic Vein)
Primary Billiary Cirrhosis
- What is it?
- In what population is it most common?
- What marker is present?
- How does it present?
Autoimmune destruction of intrahepatic bile ducts
Women
Antimitochondrial antibodies
Features of obstructive jaundice
Primary Sclerosing Cholangitis
- What is it?
- What population is it usually seen in?
- How is it seen on histology and imaging?
- What marker is present?
- What is it associated with?
- Inflammation and fibrosis of intrahepatic and extrahepatic bile ducts
- Men > Women
- ‘Onion skin’ fibrosis & ‘beaded appearance’
- P-ANCA
- Ulcerative Colitis
Small Intestine Bacterial Overgrowth (SIBO) results is deficiency of nearly all vitamins.
Which vitamins are elevated in SIBO? (2)
1. Folate (B9)
2. Vitamin K
Patients with cystic fibrosis often have pancreatic insufficiency.
What would be seen in the stool of a patient with pancretic insufficiency?
Low Fecal Elastase
Anal Fissures
- Above or Below Pectinate line?
- How does it present?
- Is the tear anterior/posterior/lateral?
- Below Pectinate line
- Pain while Pooping, blood on toilet paper
- Posterior midline tear
The “P”s of Anal Fissures
What is the most common cause of intussusception in:
- Children
- Adults
- Children: Meckels Divirticulum
- Adults: Tumor
What are the 2 types of neoplatic colonic polyps?
What polyp characteristic most correlates with increased malignancy risk?
Adenomatous & Serrated
Increasing polyp size
Which polyp would be more neoplastic:
Villous or Tubular Adenomatous Polyp?
Villous is more neoplastic than tubular
NOTE: Adenomatous and Serrated Polyps are the 2 types of neoplastic polypls.
What side of the colon would the lesion for Colon adenocarcimona be present on if the patient presents with:
- Iron-deficiency anemia
- Obstructive colon symptomps (constipation, distention)
- Iron deficiency anemia –> Right side (Ascending Colon)
- Obstruction —> Left Side (Sigmoid Colon)
What difference would be seen on histopathology between a true and false divirticulum?
True divirticulum contain all layers
(muscosa, submucosa, muscularis, serosa)
False Divirticulum just contain the mucosa and submuca
(no muscularis and serosa layers)
A patient with cystic fibrosis has decreased proprioception, hyproreflexia and mild hemolytic anemia is most likely deficient in which vitamin? Why?
Vitamin E
Due to pancreatic insufficiency that results in malabsorption of fat soluble vitamins
Vitamin E deficiency results in increased susceptibility of neuronal and erythrocyte membranes to oxidative stress
What is the tumor marker for colon cancer?
What can it be used for?
CEA (CarcinoEmbryonic Antigen)
It is used for detecting residual disease (left-over cancer cells after treatment) and cancer recurrence
NOTE: it is NOT used for cancer diagnosis since it is elevated in other diseases as well
What is the mechanism that results in hepatocyte destruction in hepatitis?
Cytotoxic CD8 T-cells destroy the cells with HBsAg and HBcAg on their cell surfacrs.
From the following CT, what is the most likely diagnosis?
What can this diagnosis lead to?

Porcelain Gallbladder
(often causes by chronic cholecystitis)
This can lead to adenocarnioma of the gallbladder
H. Pylori infections can result in both duodenal and gastric ulcers.
Where would the H. Pylori infection be in a:
- Gastric Ulcer
- Duodenal Ulcer
- Gastric ulcer –> H. Pylori in Body/Corpus
- Duodenal ulcer –> H. Pylori in Antrum
In a patient with lactose intolerance how would the following be altered:
- Breath hydrogen content
- Stool pH
- Stool osmolality
1. Increased breath hydrogen content
(fermentation of undigested lactose produces hydrogen)
2. Decreased stool pH
(due to fermentation of undigested lactose)
3. Increased stool osmolality
(due to large amounts of undigested lactose)
Why would a patient with Crohns have a Vitamin B12 deficiency?
Due to Crohns affecting the terminal illeum where B12 is absorbed
In a patient with cholesterol gallstones what would the lab values of the followig be in the gallbladder (increased/decreased):
- Cholesterol
- Bile Acids
- Phosphatidylcholine
- Increased Cholesterol
- Decreased bile acids
- Decreased Phosphatidylcholine
(
What are the 2 causes of atrophic gastritis?
In what part of the stomach do they occur?
What complication do they each have?
1. H. Pylori Gastritis
- occurs in antrum of stomach
- can lead to gastric adenocarcinoma & MALT lymphoma
2. Autoimmune Gastritis
- occurs in body and fundus of stomach
- megaloblastic anemia and gastric adenocarcinoma
In a patient with chronic autoimmune gastritis how will the following be affected?
- Gastrin
- Stomach pH
- Parietal Cell Mass
1. Increased Gastrin
(to try and stimulate acid release from parietal cells)
2. Increased pH
(Due to lack of parietal cells secreting HCl)
3. Decreased partial cell mass
(Due to autoimmune destruction)
A patient presents unintentional weight loss and a history of peptic ulcer disease.
His stomach is biopsied and is seen in the picture below.
What is the most likely diagnosis? Why?

Diffuse-Type Gastric Adenocarcinoma
Due to the signet-ring cells (nuclei pushed to outside)
NOTE: intestinal-type is more common, forms an irregular ulcer, and is associates with H.Pylori and smoked foods

In a patient with CREST Syndrome, why does the esophageal dysmotility occur?
Due to atrophy and fibrous replacement of the esophageal muscularis
NOTE: CREST = Calcinosis, Raynaud, ED, Sceleodactyl, Teleangiectasia
A patient presents with dysphagia.
On endoscopy multiple stacked circular indentations and white papules are seen along his esophagus.
What would likely be seen on biopsy of the esophagus?
Eosinophilic Infiltration of the esophageal mucosa
This patient has Eosinophilic Esophagitis
A 5 year old boy is being evaluated for poor weight since birth, he has bulky and greasy stools and a jejunal biopsy is shown below.
What is the likely diagnosis? Why?

Abetaliproteinemia
(lack of ApoB 48 & 100)
Lipids in the small intestine cant be transported into blood since they cant form chylomicrons so they accumulate in intestinal epithelium
Thats why theres entrocytes with clear cytoplasm

Lynch Syndrome (Heridetary Nonpolyposis Colorectal Carcinoma)
- What causes it?
- What else is it associated with?
- What side of the colon is it most likely on?
- What gene mutation causes it?
- Mutations in DNA mismatch repair enzymes
- Can also cause Endometrial and Ovarian Cancers
- Right sided
- MSH2, MSH6, MLH1
What type of GI ulcer is NOT associated with increased risk of carcinoma?
Duodenal Ulcer
A patient presents with LLQ pain and and a segment of her sigmoid colon is resected and shown below.
What is the most liklely diagnosis?
What risk factors can increase the risk of this happening?

Colonic Diverticulitis
Risk factors:
- eating lots of meat and fatty foods
- Low fiber diet
- obesity
- smoking and sedentary lifestyle