gastrointestinal infections

Question 1

GI infections

second most common cause of esophagitis after GERD

Answer 1

infectious esophagitis

Question 2

most common causes of infectious esophagitis

Answer 2

1. candida!!! (88%)
2. herpes simplex virus (10%)
3. cytomegalovirus (2%)

Question 3

esophageal infections

in healthy individuals…

Answer 3

most often due to HERPES SIMPLEX VIRUS

Question 4

infectious esophagitis

________ is the leading cause in HIV patients

Answer 4

candida

Question 5

gross description of candidiasis

Answer 5

1. white or yellow patches measuring <1cm
2. resemble cottage cheese

Question 6

microscopic (histologic) description of candidiasis

Answer 6

1. erosive esophagitis pattern of injury
2. acute inflammation
3. intraepithelial neutrophilic abscesses
4. epithelial edema in superficial epithelial layers

Question 7

infectious esophagitis

presence of yeast cells and pseudohyphae

Answer 7

candidiasis

Question 8

infectious esophagitis

gross description of herpes virus

Answer 8

1. punched-out ulcers, with size varying from a few milimeters up to 2 cm
2. most lesions located in MIDDLE TO DISTAL ESOPHAGUS

Question 9

infectious esophagitis

histologic findings of herpes virus

Answer 9

1. only present at the edge of the ulcer
2. ulcer bed demonstrates prominent necrosis and acute inflammatory cell infiltrate
3. marked mononuclear cell infiltrates adjacent to infected squamous epithelium

Question 10

infectious esophagitis

herpes virus histology in infected squamous epithelial cells

Answer 10

1. molding of nuclear contours
2. margination of chromatin to the periphery of nuclei
3. multinucleation

Question 11

infectious esophagitis

characteristic intranuclear inclusions of herpes virus

Answer 11

Cowdry type A: acidophilic inclusion with surrounding clear halo

Question 12

infectious esophagitis

it is rare in immunocompetent patients but causes serious disease in the setting of immunosuppression

Answer 12

cytomegalovirus

Question 13

infectious esophagitis/CMV

histologic findings in CMV

Answer 13

1. characteristic nuclear and cytoplasmic inclusions
2. infected cells are enlarged and show both cytoplasmic and nuclear inclusions

Question 14

infectious esophagitis

describe cytoplasmic inclusions in CMV

Answer 14

basophilic or amphophilic granules that are PAS and positive

Question 15

infectious esophagitis

describe nuclear inclusions in CMV

Answer 15

large, round, glassy, eosinophilic structures that may be surrounded by a halo creating an owl-eye appearance

Question 16

infectious enterocolitis

general cause of pseudomembranous colitis

Answer 16

clostridioides difficile

antibiotic-associated colitis or antibiotic-associated diarrhea

Question 17

infectious enterocolitis

large exoproteins produced by clostridioides difficile

Answer 17

toxin A and B

toxins bind to cell surface receptors and are internalized into the cell

Question 18

infectious entrocolitis

pathophysiology of pseudomembranous colitis

Answer 18

1. release in the colon, toxin bind to cell surface receptors and are internalized into the cell
2. glycosylation of small proteins occurs inside the cells involved in signaling and regulating pathways

Question 19

infectious enterocolitis

microscopic description of pseudomembranous colitis

Answer 19

1. inflammatory and ischemic features
2. volcano or mushroom-like eruption of fibrin, mucin and inflammatory cells, mainly neutrophils –> pseudomembrane overlying the injured mucosa
3. epithelium with ischemic appearance w/ attenuated/ withered crypts
4. superficial lamina propria with dense neutrophils and some capillary fibrin thrombi
5. adjacent epithelium may show active colitis or hemorrhage

Question 20

infectious enterocolitis - pseudomembranous colitis

risk factors for C. difficile-associated colitis

Answer 20

1. antibiotic treatment
2. advanced age
3. hospitalization
4. immunosuppression

Question 21

infectious enterocolitis

presentation of patients with pseudomembranous colitis

Answer 21

1. fever
2. leukocytosis
3. abdominal pain
4. cramps
5. watery diarrhea
6. dehydration

Question 22

pseudomembranous colitis

potentially fatal complication resulting from marked injury of the colonic wall

Answer 22

toxic megacolon

c. difficile

Question 23

gross description of acute viral hepatitis

Answer 23

liver normal in size, enlarged (due to inflammation) or shrunken in cases associated with acute liver failure and massive liver necrosis

Question 24

swollen liver, wrinkled capsule due to parenchymal collpase, small regenerative nodules, no fibrosis

Answer 24

severe acute hepatitis