GI - Pathology (Hirschsprung disease & other intestinal disorders) Flashcards
Pg. 357 in First Aid 2014 Sections include: -Hirschsprung disease -Other intestinal disorders
What defines/characterizes Hirschsprung disease? What causes it?
Congenital megacolon characterized by lack of ganglion cells/enteric nervous plexuses (Auerback and Meissner plexuses) in segment on intestinal biopsy. Due to failure of neural crest cell migration.; Think: “of Hirschsprung as a giant spring that has sprung in the colon”
With what mutations is Hirschsprung disease associated?
Associated with mutations in the RET gene
What are 3 signs/symptoms with which Hirschsprung disease presents?
Presents with bilious emesis, abdominal distention, and failure to pass meconium in the first 48 hours of life, ultimately manifesting as chronic constipation
What is the “transition zone” of Hirschspring disease?
Dilated portion of the colon proximal to the aganglionic segment, resulting in a “transition zone”
Is the rectum involved in Hirschsprung disease?
Involves rectum
With what condition is the risk of Hirschsprung disease increased?
Risk increased with Down syndrome
How is Hirschsprung disease diagnosed? How is it treated?
Diagnosed by rectal suction biopsy; Treatment: resection
What defines intestinal adhesion? When does it commonly form?
Fibrous band of scar tissue; commonly forms after surgery
What is the most common cause of small bowel obstruction?
Adhesion
What can be significant in the histology of intestinal adhesion?
Can have well-demarcated necrotic zones
What is angiodysplasia, and what effect can it have?
Tortuous dilation of vessels => hematochezia
At what 3 locations in the GI tract is angiodysplasia most often found? In what patient population is it more common?
Most often found in cecum, terminal ileum, and ascending colon. More common in older patients.
How is the diagnosis of angiodysplasia confirmed?
Confirmed by angiography
What signs/symptoms does duodenal atresia cause, and why?
Causes early bilious vomiting with proximal stomach distention (“double bubble” on X-ray) because of failure of small bowel recanalization
With what condition is duodenal atresia associated?
Associated with Down syndrome
What is ileus, and what signs/symptoms does it have?
Intestinal hypomotility without obstruction => constipation and decreased flatus; distended/tympanic abdomen with decreased bowel sounds.
What are 4 conditions/factors with which ileus is associated?
Associated with abdominal surgeries, opiates, hypokalemia, and sepsis
What is the pathophysiology of ischemic colitis? What major sign/symptom can it have, and why?
Reduction in intestinal blood flow causes ischemia. Pain after eating => weight loss
What are 2 locations in the colon where ischemic colitis commonly occurs?
Commonly occurs at splenic flexure and distal colon
What patient population does ischemic colitis typically affect?
Typically affects elderly
In what condition does meconium ileus occur, and what are its pathophysiology and effect?
In cystic fibrosis, meconium plug obstructs intestine, preventing stool passage at birth
What defines necrotizing enterocolitis, and what is a possible complication?
Necrosis of intestinal mucosa and possible perforation.
What part of the GI tract is usually involved in necrotizing enterocolitis, and what parts can be involved?
Colon is usually involved, but can involve entire GI tract
In what patient population is necrotizing enterocolitis more common, and why?
In neonates, more common in preemies (low immunity)
