Lecture 8: Pediatric GI Pathology Flashcards
What is the difference between atresia and stenosis?
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
What disorders can result in multiple atresias along GI tract?
- cystic fibrosis
2. gastroschisis
What are esophageal atresias usually associated with?
Trachea-esophageal fistulas
Associated with trisomy 21, 13, 18
50% of children have other congenital anomalies
VATER association
What is the clinical presentation of esophageal atresia + TE fistula?
Aspiration
Regurgitation
Respiratory distress with initial feeds
Why doesn’t lecturer cover stomach stenosis/atresia?
Cuz shits rare as fuck
What is the double-bubble sign on radiographs?
When you see two pockets of air in the duodenum/stomach
Seen in DUODENAL STENOSIS
If vomiting produces acidic contents, the duodenal stenosis is?
Proximal to the Ampulla of Vater
If vomiting produces bilious contents, the duodenal stenosis is?
Distal to the ampulla of vater
Where do most cases of duodenal stenosis occur?
Ampulla of vater (near it)
What is an annular pancreas?
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
What does it mean to have a stenosis due to a web?
It means gut tube had not fully recanalized
What are the characteristics of jejuno-ileal atresias?
85% are single, 15% are multiple
Due to intrauterine vascular accidents
What is abdominal distension?
When substances such as air or fluid accumulate in abdomen, causing outward expansion beyond normal girth
What do proximal atresias of jejuno-ileum result in?
Vomiting
What do distal atresias of jejuno-ileum result in?
Abdominal distension
Dilated loops on radio graph
What are the characteristics of anorectal atresia?
Least common
Imperforate ani
What is the levator sling?
The levator ani that supports the pelvic viscera
What are low atresias associated with? High atresias?
Perineal fistulae
Genito-urinal tract
High and low are divided by levator sling or levator ani
What is omphalocele?
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
What is gastroschisis?
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
What are the characteristics of short bowel syndrome?
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
What are the characteristics of GI duplications?
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
What is the most common GI congenital malformation?
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
What are the characteristics of Meckel’s diverticulum?
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
What is the neurenteric canal?
During the development of the notochord, the neurenteric canal is the communication between the amnion and the yolk sac
What are the characteristics of neurenteric remnants or cysts?
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!!!!!!!!!
What is hypertrichosis?
Abnormal amount of hair growth
What is pseudoobstruction?
Signs and symptoms resembling physical obstruction to luminal flow without true mechanical obstruction
Abnormal motility of bowel
What are the types of pseudoobstruction?
- Primary
i. enteric neuropathies (hirschprung)
ii. visceral myopathies (something is wrong with muscle) - Secondary
- infections
What is Hirschspring disease?
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
Where does the innervation of the colon get derived from? Significance?
They come from vagal neural crest cells
If neural crest cells don’t migrate, then you get aganglionosis
What is necrotizing enterocolitis?
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
What is pneumatosis?
Gas in the bowel wall
Characteristic of NEC (necrotizing enterocolitis)
What is intussusception?
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
What is the intussuscipiens?
The portion of the intestine
Which another part is invaginated
(distal part of intussusception)
What is the intussusceptum?
The portion of intestine that has
Prolapsed (proximal part of
The intussusception)
What can cause intussusception?
- masses
- meckels diverticulum
- lymphoid hyperplasia
What are the effects of CF on the GI tract?
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
