Lecture 8: Pediatric GI Pathology

Question 1

What is the difference between atresia and stenosis?

Answer 1

Atresia is COMPLETE obstruction and discontinues the segment
Stenosis is less common and partially obstructs lumen
Both will manifest in vomiting, abdominal distension
Both can occur anywhere along the GI tract

Question 2

What disorders can result in multiple atresias along GI tract?

Answer 2

1. cystic fibrosis

2. gastroschisis

Question 3

What are esophageal atresias usually associated with?

Answer 3

Trachea-esophageal fistulas
Associated with trisomy 21, 13, 18
50% of children have other congenital anomalies
VATER association

Question 4

What is the clinical presentation of esophageal atresia + TE fistula?

Answer 4

Aspiration
Regurgitation
Respiratory distress with initial feeds

Question 5

Why doesn’t lecturer cover stomach stenosis/atresia?

Answer 5

Cuz shits rare as fuck

Question 6

What is the double-bubble sign on radiographs?

Answer 6

When you see two pockets of air in the duodenum/stomach

Seen in DUODENAL STENOSIS

Question 7

If vomiting produces acidic contents, the duodenal stenosis is?

Answer 7

Proximal to the Ampulla of Vater

Question 8

If vomiting produces bilious contents, the duodenal stenosis is?

Answer 8

Distal to the ampulla of vater

Question 9

Where do most cases of duodenal stenosis occur?

Answer 9

Ampulla of vater (near it)

Question 10

What is an annular pancreas?

Answer 10

When the second part of duodenum is surrounded by a ring of pancreatic tissue continue with head of pancreas
Leads to Duodenal stenosis
Two ventral buds

Question 11

What does it mean to have a stenosis due to a web?

Answer 11

It means gut tube had not fully recanalized

Question 12

What are the characteristics of jejuno-ileal atresias?

Answer 12

85% are single, 15% are multiple

Due to intrauterine vascular accidents

Question 13

What is abdominal distension?

Answer 13

When substances such as air or fluid accumulate in abdomen, causing outward expansion beyond normal girth

Question 14

What do proximal atresias of jejuno-ileum result in?

Answer 14

Vomiting

Question 15

What do distal atresias of jejuno-ileum result in?

Answer 15

Abdominal distension

Dilated loops on radio graph

Question 16

What are the characteristics of anorectal atresia?

Answer 16

Least common

Imperforate ani

Question 17

What is the levator sling?

Answer 17

The levator ani that supports the pelvic viscera

Question 18

What are low atresias associated with? High atresias?

Answer 18

Perineal fistulae
Genito-urinal tract
High and low are divided by levator sling or levator ani

Question 19

What is omphalocele?

Answer 19

Defect of abdominal wall
Lead to intestinal atresia
Failure of closure of umbilical ring (when intestinal loop goes back inside of the abdomen)
Sac is still covering the contents, umbilical cord IS involved

Question 20

What is gastroschisis?

Answer 20

Absence of a sac covering the contents of the abdomen
Occurs when umbilicus closes normally but the muscles of the peritoneum don’t develop, leaving a hole from which shit can come through
NO UMBILICAL CORD

Question 21

What are the characteristics of short bowel syndrome?

Answer 21

The sequelae of stenosis and atresia
Results from massive loss of bowel so you have decreased ability to absorb nutrients
Diarrhea
Requires TPN (total parenteral nutrition)
Most common indication for bowel transplantation

Question 22

What are the characteristics of GI duplications?

Answer 22

Most common in the terminal ileum
May be cystic or tubular (the why is unknown)
Usually there is no communication between the duplications, even though they share same wall
Can be asymptomatic (tubular) or symptomatic (cyst that fills up with mucous)
Located on MESENTERIC side of bowel

Question 23

What is the most common GI congenital malformation?

Answer 23

GI diverticula
Diverticula are remnants of the vitelline (omphalomesenteric duct), which connects lumen of gut to the yolk sac
Occurs because vitelline is NOT obliterated in embryonic life
Meckel’s diverticulum is most common form
Could have oozing umbilicus if fistula

Question 24

What are the characteristics of Meckel’s diverticulum?

Answer 24

Most common congenital anomaly of gI tract
On the antimesenteric border of ILEUM
Characterized by gastric mucosa that leads to gastric acid production
This is what causes symptoms

Question 25

What is the neurenteric canal?

Answer 25

During the development of the notochord, the neurenteric canal is the communication between the amnion and the yolk sac

Question 26

What are the characteristics of neurenteric remnants or cysts?

Answer 26

Rare but occur from failure of neurenteric canal obliteration Orginate from dorsal midline GI tract Results in hyperpigmentation, hypertrichosis, GI obstruction, CNS manifestations (paralysis) and respiratory distress, CHEMICAL MENINGITIS Communication between gut and spinal cord!!!!!!!!!

Question 27

What is hypertrichosis?

Answer 27

Abnormal amount of hair growth

Question 28

What is pseudoobstruction?

Answer 28

Signs and symptoms resembling physical obstruction to luminal flow without true mechanical obstruction Abnormal motility of bowel

Question 29

What are the types of pseudoobstruction?

Answer 29

1. Primary i. enteric neuropathies (hirschprung) ii. visceral myopathies (something is wrong with muscle) 2. Secondary - infections

Question 30

What is Hirschspring disease?

Answer 30

``` Aganglionosis Lack of innervation so no peristalsis So you have a huge fucking colon Distal hindgut Presents in neonates, so won’t pass meconium Associated with RET and Down’s syndrome Nerve fibers there but no myelin sheath ```

Question 31

Where does the innervation of the colon get derived from? Significance?

Answer 31

They come from vagal neural crest cells | If neural crest cells don’t migrate, then you get aganglionosis

Question 32

What is necrotizing enterocolitis?

Answer 32

Leads to very low birth weight NEC is abbreviation Due to intestinal ischemia and bacterial colonization of gut No one knows what the cause is Signs include bloody stools, apnea, abdominal distension, gas in bowel wall (pneumatosis in radiology) 5-15% mortality so emergency Healing may result in fibrous strictures and atresia and short bowel syndrome

Question 33

What is pneumatosis?

Answer 33

Gas in the bowel wall | Characteristic of NEC (necrotizing enterocolitis)

Question 34

What is intussusception?

Answer 34

Results from invagination of one intestinal segment into another Most common cause of intestinal obstruction in childhood Leads to ISCHEMIA Constrict in venous outflow and arterial input, so you can get necrotization Child will draw up knees to chest to reduce the pain

Question 35

What is the intussuscipiens?

Answer 35

The portion of the intestine Which another part is invaginated (distal part of intussusception)

Question 36

What is the intussusceptum?

Answer 36

The portion of intestine that has Prolapsed (proximal part of The intussusception)

Question 37

What can cause intussusception?

Answer 37

1. masses 2. meckels diverticulum 3. lymphoid hyperplasia

Question 38

What are the effects of CF on the GI tract?

Answer 38

Mutation in the CFTR gene GI and nutritional abnormalities (malnutrition because cant absorb shit) Meconium can be very thick, so can obstruct the neonate bowel Can lead to rupture of intestinal wall and meconium can leak out CF can lead to atrophy of the exocrine pancreas (because you need chloride channel to secrete secretin) Malnutrition from CF leads to hepatic diseases, such as hepatomegaly, cirrhosis, or steatosis