Small Bowel - Pathoma

Question 1

What condition is duodenal atresia associated with?

Answer 1

Down Syndrome

Question 2

What are the three clinical features of Duodenal atresia?

Answer 2

• Polyhydramnios
• Distension of stomach and blind loop of duodenum
  
  • “double-bubble” sign
• Bilious vomiting

Question 3

Is Meckel Diverticulum a “true” diverticulum or “false” diverticulum?

Answer 3

True

Question 4

A Meckel Diverticulum arises due to what?

Answer 4

failure of the vitelline duct to involute

Question 5

What is the most common congenital anomaly of the GI tract?

Answer 5

Meckel Diverticulum

Question 6

What are the two most common locations for a Volvulus?

Answer 6

• Sigmoid colon
  
  • elderly
• Cecum
  
  • young adults

Question 7

What type of processes are associated with the production of intussusception in children and in adults?

Answer 7

• Leading edge!
  
  • in children → most common cause is lymphoid hyperplasia (due to infection and consequent growth of Peyer’s patches)
    
    • terminal ileum to cecum
  • in adults → most common cause is tumor

Question 8

What are the three key clinical features of Small Bowel Infarction?

Answer 8

1. Abdominal pain
2. Bloody diarrhea
3. Decreased bowel sounds

Question 9

Which HLA types is Celiac Disease associated with?

Answer 9

HLA DQ2 and DQ8

Question 10

How does tissue damage occur in Celiac disease?

Answer 10

• Gluten in ingested
• Gliadin is deamidated by tTG
• APCs ingest gliadin
• APCs present gliadin to Helper T cells via MHC II
• Helper T cells mediate tissue damage in the small bowel

Question 11

What skin condition is associated with Celiac Disease? What causes it?

Answer 11

Dermatitis Herpetiformis

• Due to IgA deposition at tips of dermal papillae

Question 12

What are the laboratory findings in Celiac Disease?

Answer 12

• IgA antibodies against:
  
  • endomysium (connective tissue that sheathes each muscle fiber)
  • tTG (tissue trans-glutaminase)
  • gliadin
• IgG antibodies are useful for diagnosis in IgA deficiency

Question 13

Patient’s with Celiac disease are at an increased of developing what neoplasias?

Answer 13

• Small bowel carcinoma
• T-cell lymphoma (EATL)

***Presents as refractory disease despite good dietary control!

Question 14

Where is the bowel damage most prominent in Tropical Sprue?

Answer 14

more in the jejunum and ileum

Question 15

What part of the small bowel does Whipple’s Disease most affect?

Answer 15

lamina propria

Question 16

Besides the small bowel, what additional sites are affected by Whipple’s Disease?

Answer 16

• Synovium of joints
• Cardiac valves
• Lymph nodes
• CNS

Question 17

What is Abetalipoproteinemia?

Answer 17

• Autosomal recessive deficiency of apolipoprotein B-48 (chylomicron) and B-100 (VLDL/LDL)

Question 18

What is a Carcinoid Tumor?

Answer 18

• Malignant proliferation of neuroendocrine cells
• Low-grade malignancy

Question 19

What immunohistochemical stain are carcinoid tumor cells positive for?

Answer 19

Chromogranin

Question 20

What is the appearance of carcinoid tumors?

Answer 20

• Submucosal polp-like nodule
• Can arise anywhere along the gut, but the small bowel is the most common site

Question 21

What hormone is most often secreted by Carcinoid Tumors?

Answer 21

Serotonin

• 5-HIAA (metabolite) is excreted in the urine
• not carinoid syndrome until tumor metastasizes to liver (5HT has to enter systemic circulation)

Question 22

What are the symptoms of Carcinoid Syndrome?

Answer 22

• Bronchospasm
• Diarrhea
• Flushing of the skin
• All symptoms can be triggered by EtOH or emotional stress

Question 23

What is Carcinoid Heart Disease?

Answer 23

• Right-sided valvular fibrosis
  
  • due to metastasis of carcinoid tumor to the liver
  • leads to tricuspid regurgitation and pulmonary valve stenosis
• No left-sided disease because lung has MAO to degrade serotonin before it enters right side