GI - Pathology (Malabsorption syndromes)

Question 1

What are 5 signs/symptoms that malabsorption syndromes can cause?

Answer 1

Can cause (1) diarrhea, (2) steatorrhea, (3) weight loss, (4) weakness, and (5) vitamin and mineral deficiencies; Think: “These Will Cause Devastating Absorption Problems”

Question 2

To what other condition does Tropical sprue have similar findings? How is it different?

Answer 2

Similar findings as celiac sprue (affects small bowel), but responds to antibiotics

Question 3

What is the cause of Tropical sprue? In patients with what exposure/history is it seen?

Answer 3

Cause is unknown, but seen in residents of or recent visitors to tropics

Question 4

What pathogen causes Whipple disease? What is its Gram stain?

Answer 4

Infection with Tropheryma whipplei (gram positive)

Question 5

What are 3 key histologic findings of Whipple disease?

Answer 5

(1) PAS (+) (2) foamy macrophages in intestinal lamina propria, (3) mesenteric nodes

Question 6

What are 3 common symptoms of Whipple disease?

Answer 6

(1) Cardiac symptoms (2) Arthralgias and (3) Neurologic symptoms are common.; Think: “Foamy (macrophages) WHIPPed cream in a CAN”

Question 7

In what patient population does Whipple disease most often occur?

Answer 7

Most often occurs in older men

Question 8

What defines celiac sprue?

Answer 8

Autoimmune-mediated intolerance of gliadin (wheat) leading to malabsorption and steatorrhea

Question 9

With what 2 HLA markers is Celiac sprue associated? With what ethnicity is it associated?

Answer 9

Associated with HLA-DQ2, HLA-DQ8, and northern European descent

Question 10

What are 6 histologic/lab/clinical findings that characterize Celiac sprue?

Answer 10

Findings include (1) anti-endomysial, (2) anti-tissue transglutaminase, and (3) anti-gliadin antibodies; (4) blunting of villi; and (5) lymphocytes in lamina propria. (6) Decreased mucosal absorption that primarily affects distal duodenum and/or proximal jejunum

Question 11

What is used to diagnose Celiac sprue?

Answer 11

Serum levels of tissue transglutaminase antibodies are used for diagnosis

Question 12

With what skin condition is Celiac sprue associated? What kind of risk does Celiac sprue increase? Give an example of this risk.

Answer 12

Associated with dermatitis herpetiformis; Moderately increased risk of malignancy (e.g., T-cell lymphoma)

Question 13

How is Celiac sprue treated?

Answer 13

Treatment: gluten-free diet

Question 14

What is the most common disaccharidase deficiency, and what effect does it have?

Answer 14

Most common is lactase deficiency => milk intolerance

Question 15

Describe the key histologic finding in disaccharidase (lactose) deficiency. What is its major symptom?

Answer 15

Normal-appearing villi. Osmotic diarrhea.

Question 16

Where in the intestine is lactase located? Give this, how can self-limited lactase deficiency occur?

Answer 16

Since lactase is located at tips of intestinal vili, self-limited lactase deficiency can occur following injury (e.g., viral diarrhea)

Question 17

What test is used for lactase deficiency? What are 2 criteria for determining that a patient is positive for lactase deficiency?

Answer 17

Lactose intolerance test: (+) for lactase deficiency if: (1) Administration of lactose produces symptoms and (2) Glucose rises < 20 mg/dL

Question 18

What is the pathophysiology of Abetalipoproteinemia, and what effect does it have?

Answer 18

Decreased synthesis of apolipoprotein B => inability to generate chylomicrons => decreased secretion of cholesterol, VLDL into bloodstream => fat accumulation in enterocytes

Question 19

When does Abetalipoproteinemia present, and what are 5 of its signs/symptoms?

Answer 19

Presents in early childhood with failure to thrive, steatorrhea, acanthocytosis, ataxia, night blindness

Question 20

What are 3 causes of pancreatic insufficiency?

Answer 20

Due to cystic fibrosis, obstructing cancer, and chronic pancreatitis

Question 21

What effects does pancreatic insufficiency have?

Answer 21

Causes malabsorption of fat and fat-soluble vitamins (vitamins A, D, E, K)

Question 22

What stool finding is associated with pancreatic insufficiency?

Answer 22

High neutral fat in stool

Question 23

What clinical test is relevant to pancreatic insufficiency? What kind of result is expected with pancreatic insufficiency? In what other contexts/conditions is this result different?

Answer 23

D-xylose absorption test: normal urinary excretion in pancreatic insufficiency; decreased excretion with intestinal mucosa defects or bacterial overgrowth