GI - Pathology (GI Diverticula, Intussuception, & volvulus)

Question 1

What defines diverticulum?

Answer 1

Blind pouch protruding from the alimentary tract that communicates with the lumen of the gut

Question 2

How do most diverticula arise, in what parts of the GI tract, and what kind of diverticula are they? Where do diverticula most often arise?

Answer 2

Most diverticula (esophagus, stomach, duodenum, colon) are acquired and are termed “false” in that they lack or have an attenuated muscularis externa. Most often in sigmoid colon.

Question 3

What defines a “true” diverticulum? Give an example.

Answer 3

“True” diverticulum - all 3 gut wall layers outpouch (e.g., Meckel)

Question 4

What defines a “false” diverticulum? What is another name for this? Where do these diverticula especially occur?

Answer 4

“False” diverticulum or Pseudodiverticulum - only mucosa and submucosa outpouch. Occur especially where vasa recta perforate muscularis externa.

Question 5

What defines diverticulosis, and where is it commonly found?

Answer 5

Many false diverticula of the colon, commonly sigmoid

Question 6

How common is diverticulosis, and in what age group does it frequently occur?

Answer 6

Common (in ~50% of people > 60 years)

Question 7

What causes diverticulosis? With what behavior/condition is it associated?

Answer 7

Caused by increased intraluminal pressure and focal weakness in colonic wall. Assoicated with low-fiber diets.

Question 8

How does diverticulosis often present? Of what symptom/sign is it a common cause?

Answer 8

Often asymptomatic or associated with vague discomfort. A common cause of hematochezia.

Question 9

What are 2 complications of diverticulosis?

Answer 9

Complications include diverticulitis, fistulas.

Question 10

What is diverticulitis, and what are 3 signs/symptoms classically associated with it?

Answer 10

Inflammation of diverticula classically causing LLQ pain, fever, leukocytosis.

Question 11

What are 2 possible complications of diverticulitis? What may result from each?

Answer 11

(1) May perforate => peritonitis, abscess formation, or bowel stenosis (2) May also cause colovesical fistual (fistual with bladder) => pneumaturia

Question 12

How is diverticulitis treated?

Answer 12

Give antibiotics

Question 13

What stool finding(s) is (are) common in diverticulitis?

Answer 13

Stool occult blood is common +/- hematochezia

Question 14

What is diverticulitis sometimes called with regard to its presentation, and why?

Answer 14

Sometimes called “left-sided appendicitis” due to overlapping clinical presentation

Question 15

What kind of diverticulum is Zenker diverticulum?

Answer 15

Pharyngoesophageal false diverticulum.

Question 16

What causes Zenker diverticulum, and where exactly does it occur?

Answer 16

Herniation of mucosal tissue at Killian triangle between the thyropharyngeal and cricopharyngeal parts of the inferior pharyngeal constrictor

Question 17

What are 3 presenting symptoms of Zenker diverticulum?

Answer 17

Presenting symptoms: dysphagia, obstruction, foul breath from trapped food particles (halitosis).

Question 18

In what patient population is Zenker diverticulum most common?

Answer 18

Most common in elderly males

Question 19

What may Zenker diverticulum show on barium swallow?

Answer 19

Barium swallow shows contrast filling false diverticulum originating from posterior esophagus

Question 20

What kind of diverticulum is Meckel diverticulum?

Answer 20

True diverticulum

Question 21

What causes Meckel diverticulum? What may it contain?

Answer 21

Persistence of vitelline duct. May contain ectopic acid-secreting gastric mucosa and/or pancreatic tissue.

Question 22

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

Answer 22

Meckel diverticulum

Question 23

What are 5 signs/symptoms/results of Meckel diverticulum?

Answer 23

Can cause melana, RLQ pain, intussusception, volvulus, or obstruction near the terminal ileum

Question 24

To what other abnormality of the vitelline duct can meckel diverticulum be contrasted, and what defines this other abnormality?

Answer 24

Contrast with omphalomesenteric cyst = cystic dilation of vitelline duct

Question 25

How is Meckel diverticulum diagnosed?

Answer 25

Diagnosis: pertechnetate study for uptake by ectopic gastric mucosa

Question 26

What is the mnemonic associated with Meckel diverticulum?

Answer 26

Think: "The FIVE 2's: 2 inches long, 2 feet from the ileocecal valve, 2% of population, commonly presents in first 2 years of life, may have 2 types of epithelial (gastric/pancreatic)."

Question 27

What is intussusception, and where does it commonly occur?

Answer 27

"Telescoping" of 1 bowel segment into distal segment, commonly at ileolcecal junction

Question 28

How does intussusception often present, and what causes this?

Answer 28

Compromised blood supply => intermittent abdominal pain often with "currant jelly" stool

Question 29

In what patient populations is intussusception unusual versus common? For each of these populations, with what is intussusception associated?

Answer 29

Unusual in adults (associated with intraluminal mass or tumor that acts as a lead point that is pulled into the lumen). Majority of cases occur in children (usually idiopathic; may be associated with recent enteric or respiratory viral infection).

Question 30

How is the clinical approach to intussusception in children?

Answer 30

Abdominal emergency in early childhood

Question 31

What is volvulus? What complications can it cause?

Answer 31

Twisting of portion of bowel around its mesentery; can lead to obstruction and infarction

Question 32

Where in the GI tract can volvulus occur?

Answer 32

Can occur throughout the GI tract.

Question 33

Which type of volvulus is more in common in infants and children versus the elderly?

Answer 33

Midgut volvulus more common in infants and children. Sigmoid volvulus more common in elderly.