Path-Diarrhea

Question 1

this infection results in infiltration of small bowel mucosa with macrophages that cannot destroy the bacteria, resulting in abundant pale granular cytoplasm

Answer 1

whipple’s dz

Question 2

macrophage cytoplasm in whipple’s dz is highlighted with this stain

Answer 2

PAS (look DARK pink all over)

Question 3

in whipple’s dz, expansion of the lamina propria with numerous macrophages results in the impression of a…

Answer 3

flat mucosa

Question 4

what is found scattered throughout the lamina propria in Whipple’s dz?

Answer 4

variably-sized clear spaces, representing lipid droplets

Question 5

who get’s whipple’s dz?

Answer 5

males 8-10x more likely, usually white, 40-50 yrs old

Question 6

microbiology of whipple’s dz bacteria

Answer 6

actinomycetes, gram positive bacteria that can form filaments

Question 7

what diarrhea pattern is seen in whipple’s?

Answer 7

chronic and malabsorptive

Question 8

CMV/HSV infection most common in _____

Answer 8

immunocompromised

Question 9

tissue damage from CMV is due to..

Answer 9

ischemic necrosis of mucosa and ulceration

Question 10

what cells are usually affected by CMV

Answer 10

endothelial cells and fibroblasts

Question 11

microscopic findings of CMV

Answer 11

cytomegaly, eosinophilic inclusions (intranuclear and cytoplasmic)

Question 12

which parts of the GI tract are affected by HSV

Answer 12

squamous epithelium of esophagus or anal canal

Question 13

gross pathology of both CMV and HSV shows?

Answer 13

small, shallow ulcers with white necrotic debris and red border

Question 14

basophilic “ground-glass” intranuclear inclusions found in multinucleated epithelial cells suggests?

Answer 14

HSV infection

Question 15

4 M’s of HSV (Herpetic viral cytopathic effect)

Answer 15

1. Megaly (big), 2. multinucleated, 3. nuclear molding, 4. chromatin margination (ground glass nucleoplasm with viral particles)

Question 16

this protozoan parasite causes self-limiting acute, watery, non-bloody diarrhea in immunocompetent

Answer 16

cryptosporidium parvum

Question 17

how would you detect crypto histologically?

Answer 17

tiny, round PAS+ organisms inside vacuoles located on the brush border of many GI organs

Question 18

host response to crypto

Answer 18

increased lymphocytes in lamina propria, mild epithelial damage (can cause villous atrophy and neutrophilic infiltration in severe cases)

Question 19

this infection causes increased shedding of infected cells, resulting in surface epithelium with even worse malabsorption

Answer 19

cryptosporidium parvum

Question 20

Of crypto and giardia, which parasites resist chlorination? Are removed by filtration?

Answer 20

both; giardia

Question 21

pathogenesis of giardia

Answer 21

trophozoites adhere to mucosal surface, forming physical barrier to absorption and damaging brush border such that short-term enzyme deficiencies develop

Question 22

how can giardia trophozoites be recognized on histo?

Answer 22

pear or leaf shaped parasites floating in mucus and on mucosa; attach to mucosa by ventral sucker disc

Question 23

transmission of giardia

Answer 23

fecal-oral –> outdoorsy ppl consume fresh water that contains cysts (cysts reproduce to form trophozoites inside human), also daycares, homosexuals

Question 24

imprint cytology with this stain shows pear-shaped giardia trophozoites

Answer 24

Giemsa (look purply-blue)

Question 25

entamoeba is transmitted by?

Answer 25

fecal-oral

Question 26

most common site for entamoeba

Answer 26

cecum

Question 27

gross pathology of entamoeba

Answer 27

friable, red mucosa and ulceration resembling IBD

Question 28

microscopic findings of entamoeba

Answer 28

flask-shaped ulcers extend through muscularis mucosae

Question 29

complications of entamoeba infection

Answer 29

spread to liver, causing abscess

Question 30

colon biopsy of entamoeba shows?

Answer 30

trophs containing ingested RBCs (look like macrophages)

Question 31

entamoeba cysts in the stool can be stained with?

Answer 31

PAS stain

Question 32

chronic cholitis comes in two forms?

Answer 32

bloody or watery

Question 33

chronic bloody diarrhea suggests?

Answer 33

IBD or neoplasm

Question 34

chronic watery diarrhea suggests?

Answer 34

microscopic colitis (lymphocytic +/- collagenous)

Question 35

histology of microscopic colitis shows?

Answer 35

preserved architecture with lymphocytes in epithelium +/- thickened subepithelial collagen band

Question 36

what other disease is associated with lymphocytic colitis

Answer 36

celiac disease

Question 37

best way to visualize collagenous colitis

Answer 37

trichrome stain

Question 38

where do lymphocytes localize in lymphocitic colitis

Answer 38

surface of epithelium and in glands

Question 39

pathophysiology of celiac disease

Answer 39

immune mediated enterocyte damage -> crypt cells fail to regenerate -> shortened villi (note: patchy)

Question 40

where is celiac dz most severe?

Answer 40

distal duodenum and proximal jejunum (take multiple biopsies due to patchy nature)

Question 41

histologic findings in celiac

Answer 41

villous blunting (short with fused microvilli) with long crypts, increased lymphocytes and plasma cells in lamina propria, increased lymphocytes in epithelium

Question 42

dx of celiac dz

Answer 42

small bowel biopsy, gluten-free trial, serologic testing with TTG, IgA