Infection- Fungal Flashcards Preview

2H. Pathology- CNS > Infection- Fungal > Flashcards

Flashcards in Infection- Fungal Deck (16)
1

Fungal disease of the CNS is encountered primarily in _______________. 

immunosuppressed individuals

2

The
brain is usually involved when there is widespread hematogenous dissemination of the fungus,
most often ___________.

 

  • Candida albicans,
  • Mucor species,
  • Aspergillus fumigatus, and
  • Cryptococcus neoformans

3

In endemic areas, pathogens such as _______________may involve the CNS after a primary pulmonary or
cutaneous infection; again, this often follows immunosuppression.

Histoplasma capsulatum, Coccidioides
immitis,

and

Blastomyces dermatitidis 

4

There are three main patterns of fungal infection in the CNS: _____________, _________ and ________

  1. chronic meningitis,
  2. vasculitis, and
  3. parenchymal invasion.

5

 Vasculitis is most frequently seen with____________ and __________
both of which are characterized by direct fungal invasion of blood vessel walls, but it
occasionally occurs with other infections such as candidiasis.

The resultant vascular thrombosis
produces infarction that is often strikingly hemorrhagic and that subsequently becomes septic
from ingrowth of the causative fungus.

 mucormycosis and aspergillosis,

6

Parenchymal invasion, usually in the form of granulomas or abscesses, can occur with most of
the fungi and often coexists with meningitis.

 

7

The most commonly encountered fungi invading the
brain are _______ and ____________.

 

Candida and Cryptococcus

8

Candidiasis usually produces ____________. 

multiple microabscesses,
with or without granuloma formation

9

Although most fungi invade the brain by hematogenous
dissemination
, direct extension may also occur, particularly in mucormycosis, most commonly in
_____________

diabetics with ketoacidosis.

10

What is the most common fungal infecion associated in diabetics  and ketoacidosis that cause direct invasion instead of hematogenous spread.

mucormycosis

11

What is the common opportunistic infection in the setting of HIV/AIDS, may be
fulminant and fatal in as little as 2 weeks or indolent, evolving over months or years.

Cryptococcal meningitis

12

What is the CSF appearance in Cryptococcus mengitis?
 

may contain few cells but usually has a high concentration of protein.

 

13

The mucoid-encapsulated
yeasts can be visualized in the CSF by______preparations and in ______________

 India ink 

tissue sections by PAS, mucicarmine, and silver stains.

14

With cryptococcal infection, the brain shows a_______________

 

  •  chronic meningitis affecting the basal leptomeninges,
  • which are opaque and thickened by reactive connective tissue that may obstruct the outflow of CSF from the foramina of Luschka and Magendie, giving rise to hydrocephalus.

15

 Sections of the brain in cryptococcal infection disclose a ________________ which are especially
prominent in the basal ganglia in the distribution of the lenticulostriate arteries ( Fig. 28-28A ).

 

 

gelatinous material within the subarachnoid
space 
and small cysts within the parenchyma (“soap bubbles”),

 

Cryptococcal infection. A, Whole-brain section showing the numerous
areas of tissue destruction (“soap bubbles”) associated with the spread of organisms in the
perivascular spaces. B, At higher magnification it is possible to see the cryptococci in the
lesions.

 

Parenchymal lesions consist of aggregates of organisms within expanded perivascular
(Virchow-Robin) spaces associated with minimal or absent inflammation or gliosis ( Fig. 28-
28B ).

The meningeal infiltrates consist of chronic inflammatory cells and fibroblasts admixed
with cryptococci.

16