What lab findings are seen in celiac disease?
What is one of the worst possible sequelae?
Positive antibodies (IgA, IgG) against gliadin, tTG, and endomysium.
What symptoms do patients with celiac (presumably classic) present with?
Why might a microcytic anemia be seen?
Diarrhea, gas, fatigue, weight loss / failure to thrive.
As celiac disease damages the villous lining of the GI tract, it can cause malabsorption resulting in deficiencies of iron and other nutrients.
Give three histological findings seen in a biopsy of tissue affected by celiac disease.
Crypt hyperplasia (note mitoses)
Plasma cell expansion in the lamina propria.
Crohn's and ulcerative colitis can be distinguished by the expansion of different T cell populations. What are they?
Crohns - Th1
Ulcerative Colitis - Th2
Here is a series of epidemiologic traits, pathological findings, or extraintestinal signs & complications. Specify if one is found in UC or CD.
1. Creeping fat
2. History of smoking
3. Malabsorption and steatorrhea
4. Toxic megacolon
5. Primary sclerosing cholangitis
1. CD (no creeping fat seen in UC)
2. CD (smoking may be slightly protective from UC)
3. CD (UC doesn't affect small bowel, thus no malabsorption)
4. UC (generally; can be seen in Crohn's)
Here is a series of epidemiologic traits, pathological findings, or extraintestinal signs & complications. Specify if one is found in UC, CD, or both.
6. Erythema nodosum
7. Increased risk of cancer
8. "Apple-core sign"
9. Aphthous ulcers
10. Mucosal erosions
6. CD (also beware Pyroderma gangrenosum)
7. Mainly UC, but also CD if involving the colon
8. CD (due to wall thickening)
10. UC (as opposed to transmural)
What is the "pseudomembrane" is pseudomembranous colitis?
What progression of this requires surgical intervention?
Fibrinopurulent debris generated from a C. Diff infection and response.
What is diverticulitis?
Where does it occur?
Inflammation of an existing diverticulum.
Diverticula tend to occur in the lower colon, especially at the sites of vasa recta entry.
What is the defect observed in FAP?
How is it treated?
Autosomal dominant mutation of APC gene on chromosome 5.
What does ischemic injury look like on histology?
Distinguish between the causes of mucosal and tramural ischemia.
Coagulative necrosis results in "ghosting" of the intestinal villi (villi affected before crypts)
Mucosal usually due to hypoperfusion, transmural due to occlusion (thrombus, embolism)
In the context of ischemic injury, are watershed areas more or less susceptible?
It depends on the cause of ischemia. Since watershed areas are at the border of two vascular supplies, they resist occlusive ischemia but are more susceptible to hypoperfusive ischemia.
Name 4 physical forms of bowel obstruction
What is required for fat absorption?
Bile salts, pancreatic lipase, colipases.
Phospholipases and cholesterol esterases are also helpful.
Why might patients on RNY gastric bypass experience iron deficiency anemia?
Duodenal bypass means reduced absorptive surface for iron.
What vitamin deficiencies are steatorrheic patients apt to develop?