Pediatric Gastrointestinal Pathology

Question 1

Are atresias and stenoses more common in foregut or hindgut?

Answer 1

foregut

Question 2

Esophageal atresia occurs most often in association with a _____ to the trachea

Answer 2

fistula

Question 3

85-90% of atresias have a _______ and a _____ between the lower part of the esophagus and trachea

Answer 3

blind upper esophageal segment and a fistula

Question 4

Clinical presentation of atresia and fistula

Answer 4

aspiration, regurgitation, respiratory distress with initial feeds, absence of GI gas pattern on x ray, 50% of children have other anomolies, trisomy syndromes, VATER association

Question 5

Where do duodenal stenoses tend to occur?

Answer 5

proximally near the ampulla of vater

Question 6

Etiologies of duodenal stenoses

Answer 6

1. web; from failure of proper recanalization during development
2. annular pancreas: secopancreasnd portion of duodenum completely or partially surrounded by

Question 7

Clinical presentation of duodenal stenosis

Answer 7

vomiting at birth, bilious if distal to the ampulla, double bubble xray

Question 8

Are jejunoileal atresias more often single or multiple?

Answer 8

85% single

Question 9

Etiologies of jejunoileal atresias

Answer 9

intrauterine vascular accidents, volvulus, hernias, necrotizing enterocolitis

Question 10

Clinical manifestation of jejunoileal atresia

Answer 10

1. proximal = vomiting

2. distal = distension and dilated radiographic loops

Question 11

How are anorectal atresias classified?

Answer 11

high = above levator sling and associated with GU fistulae
low = associated with perineal fistulae

Question 12

2 gastric wall defects

Answer 12

1. omphalocele: covered by amniotic sac, due to failure of complete fusion of umbilical ring during withdrawal of intestine
2. gastroschisis: complete failure of formation of peritoneum, muscle, and skin of abdomen

Question 13

Short Bowel Syndrome pathogenesis

Answer 13

loss of bowel surface, reduced reabsorption, nutrient deficiency, diarrhea

Question 14

Most common indication for bowel transplant in children

Answer 14

short bowel syndrome

Question 15

Etiologies of SBS in younger children

Answer 15

congenital gastroschisis, voluvulus, atresia (60%) or NEC (40%)

Question 16

Etiologies of SBS in older children

Answer 16

volvulus, trauma, neoplasia

Question 17

GI duplication

Answer 17

development of a duplication of a segment of GI tract –> usually in mesenteric side of bowel

Question 18

What is the most common site of GI duplication?

Answer 18

terminal ileum –> usually share wall but do not communicate with intestine

Question 19

GI diverticuli are mostly located on which side of the bowel?

Answer 19

antimesenteric

Question 20

Pathogenesis of GI diverticuli

Answer 20

failure to close vitelline duct –> most common is meckel’s diverticulum

Question 21

By what week of development is the vitelline duct usually obliterated?

Answer 21

10th week

Question 22

What is inside a GI diverticulum?

Answer 22

50% contain gastric mucosa –>tend to be symptomatic because of acid damage –> rectal bleeding

Question 23

Neurenteric remnant or cyst

Answer 23

originate form dorsal midline GI tract and attach or pass through vertebrae and spinal cord

Question 24

Most common location for neurenteric remnant

Answer 24

cervical/lumbar spine

Question 25

clinical signs of neurenteric remnant

Answer 25

dorsal cutaneous hypertrichosis or hyperpigmentation + GI obstruction, respiratory distress, and CNS paralysis/infections/chemical meningitis

Question 26

Category of disorders characterized by signs and symptoms reflecting physical obstruction to luminal flow without true mechanical obstruction

Answer 26

pseudo-obstruction

Question 27

Most frequent primary enteric psuedo-obstruction

Answer 27

Hirschsprung disease

Question 28

Secondary etiologies of pseudo-obstruction

Answer 28

chagas disease, toxic megacolon, dystrophies, etc

Question 29

2 classes of primary pseudo-obstruction

Answer 29

enteric neuropathies and visceral myopathies

Question 30

The enteric nervous system arises mostly from the _____ neural crest cells which populate the gut in a cranio-caudal fashion.

Answer 30

vagal

Question 31

Failure of normal migration of enteric neural crest cells results in _____

Answer 31

aganglionisis

Question 32

Pathophysiology of aganglionosis

Answer 32

No neural crest miration = no ganglion = no propulsion in the intestine

Question 33

Hirschsprung disease incidence

Answer 33

1/5000

Question 34

Dx of Hirschsprung disease

Answer 34

finding of absence of ganglion cells in rectal biopsy

Question 35

Which 2 genes are most associated with Hirschsprung?

Answer 35

1. ret in 50% of family and 15% of sporadic

2. 10% down syndrome

Question 36

Where is Hirschsprung usually located?

Answer 36

usually distal and limited but rarely exists in the cranial intestine

Question 37

Most common GI emergency in newborns

Answer 37

necrotizing entercolitis

Question 38

T/F most infants with NEC are premature

Answer 38

T –> 90% premature and most very low birthweight

Question 39

Most important contributing factors to NEC

Answer 39

intestinal ischemia, intestinal immaturity, bacterial colonization of gut, enteral feeding

Question 40

Clinical signs of NEC

Answer 40

first 2 weeks of life: abdominal distension, bloody stools, apnea, gas in bowel wall (pneumatosis)

Question 41

Intussusception

Answer 41

results from invagination of one intestinal segment into the other

Question 42

Most common cause of intestinal obstruction in childhood

Answer 42

Intussusception

Question 43

Cystic fibrosis is AD/AR

Answer 43

recessive –> 1/3200 births

Question 44

Primary cystic fibrosis defect

Answer 44

CFTR chloride chanel

Question 45

GI effect of CF

Answer 45

thick mucus, decreased ciliary clearance, reduced Cl- secretion, less water, dilated glands, meconium ileus, pancreatic atrophy

Question 46

meconium ileus

Answer 46

obstruction of intestinal lumen by viscid meconium –> most cases occur in patients with CF