Lecture 7: Small Intestine Pathology Flashcards
What is Meckel’s Diverticulum
Generally asymptomatic 2” small bowel out-pouching that occurs about 2 ft from the colon in 2% of the population, 2 types of tissues (gastric and pancreatic)
Why would gastric tissue cause pain? How can you diagnose?
Can lead to peptic ulcer because it’s producing acid; Meckel’s scan
EXTRINSIC obstruction causes…
Ischemia of small bowel
Why must you compromise multiple vessels to create small bowel ischemia? How can this happen?
Lots of collaterals! Can happen when bowel itself is compressed
Three examples of intestinal extrinsic obstruction
Strangulated hernia, volvulus, intussusception
Stages of hernia
Reducible –> edema, lymph/venous compromise –> Incarcerated (non-reducible) –> arterial compromise –> Strangulated
Risk factors for volvulus
Adhesions (surgery), poor motility, abnormal mesentery, congenital malrotation
Describe intusseception
Leading point is mass lesion (tumor in adults, hyperplastic lymph tissue in children)
Tx for adult intussception; tx for children intussception
Surgery; retrograde barium enema
How common is celiac? How many symptomatic?
1:100; 20%
What are HLA markers of celiac’s? Are they necessary or sufficient? What is another important marker?
HLA DQ2 or DQ8; necessary; circulating IgA anti-tissue transglutaminase (TGT)
When do you measure IgA anti-tissue transglutaminase (TGT)?
At the point of diagnosis (must be eating gluten)
Celiac’s disease have problems with what kinds of absorption?
Minerals/nutrients (proximal region most implicated)
When can celiac’s strike?
Any age
Sx of celiac’s?
Steatorrhea, failure to thrive, short stature, osteoporosis, anemia, infertility
Histological finding of celiac disease (4)
Partial/total villous atrophy, intraepithelial lymphocytes, increased crypt mitoses, chronic inflammation (inflammatory cells)
Three regions for lack of absorption in celiac’s
- Attenuated glycocalyx (impaired digestion); 2. Attenuated microvilli (loss of SA); 3. Damaged organelles (impaired metabolism/absorption)
Diseases associated with celiacs (5)
Ulcerative jejunoileitis, enteropathy-associated T cell lymphoma, GI and non-GI cancers, dermatitis herpetiformis, collagenous sprue
Describe Whipple’s disease: define, cause, dx, tx
Mutlisystem disease caused by intracellular bacilli (Trophyrema whipplei) characterized by numerous foamy PAS+ macrophages; tx = PCR; rx = antibiotics
Whipple’s disease fill what kind of cell?
Macrophages
In the GI tract, Whipple’s disease causes…
Lymphatic obstruction
Describe Congenital Lymphangeiectasia
Rare genetic disease associated with malformations of lymph system causing edema, chylous ascites (due to leaking of lymph fluid into abdominal cavity), and engorged lacteals leading to malnutrition, lymphcytopenia, and recurrent infections
Small intestinal diverticulosis can cause what?
Bacterial overgrowth (due to stasis) leading to malabsorption
Two types of diverticulosis
True (congenital) and false (out-pouching due to high pressures, more often occurs in elderly)