Path III Flashcards
What is MS?
Resulting pathology?
Autoimmune inflammatory disease of the CNS
causes demyelination & variable axonal loss ; multiple lesions (plaques) involving brain & spinal cord
What are the genetic & environmental risk factors for MS?
- Genetic
- HLA-DR2
- Environmental
- temperate climate
- viruses (?)
What pathology is shown in the provided image?
MS
wel circumscribed, tan, irregularly shaped plaque in periventricular white matter (demyelinating)
If the provided sample has been stained with Luxol-fast blue PAS, it is from what disease?
MS
unstained regions of demyelination
plaques (red arrows) seen around the 4th ventricle
What features of MS plaques are depicted in the provided schematic?
- black solid arrows
- sharp borders (to right is normal tissue)
- white solid arrow
- macrophages, both interstitial & perivascular
- black open arrow
- perivascular chronic inflammation
- scattered large stellate reactive astrocytes complete the picture
What patholgy is shown in the provided images? This is suspicious of what conditin?
- Left
- perivascular lymphocytes (active MS)
- Right
- perivascular cuff of macrophages (suspicious demyelinating disease or infarct)
- intraparenchmal phagocytes
If the provided sample has been stained with Luxol-fast blue PAS, it is from what disease?
sharp interface between lesion- demyelination - (left) and normal parenchyma (right)
What is ADEM?
It is associated with what conditions?
Acude Disseminate Encephalomyelitis
brief but widespread demyelinating disease in the brain & spinal cord (mainly in children)
post-infectious/post-vaccinial/allergic encephalomyelitis
usually follows URI
PML is cause by what virus?
JC polyoma virus
Describe the pathophysiology of PML
deadly demyelinating CNS disease due ot lytic infection of oligodendrocytes
- infection acquired young age
- virus lies dormant in kidneys & lympohoid
- cellular immunity suppressed -> virus is reactivated
related to AIDS & immunosuppressive therapies
What pathology is shown im the provided images?
PML
- Left
- early lesions are ovoid, yellow-tan demyelinated foci along cortical gray-white junction (black arrows)
- Right
- older, tan-gray lesions coalesent and depressed (black arrows)
What pathology is shown in the provided images?
Advanced stage PML
large areas of cerebral white matter have depressed, cavitated areas w/ granular appearance (black open arrow)
What type of cells do see in this microscopic sample?
They are classic expression of what?
homogenized nuclei of oligodendrocytes
classic expression viral infections (ie. PML)
What is central pontine myelinolysis?
degeneration of a symmetrical midline portion of the basis pontis & portions of pontine tegmentum
loss of myelin w/ relative preservation of axons & neuronal cell bodies
Central pontine myelinolysis is most commonly seen in what situations?
rapid correction hyponatremia
What condition is seen in the provided image?
Central pontine myelinolysis
myelin loss without evidence of inflammation
all lesions appear at same stage of myelin loss & reaction
What pathology is shown in the provided image?
focal watershed infarct
What cause of infarct is shown in the provided image?
in situ thrombosis
Other than atherosclerosis, what are the other common causes of thrombosis?
Cardiac mural thrombi
Vasculitis (infectious & non-infectious)
What pathology is shown in the provide image?
Hemorrhagic Infarct: shower emboli
What pathology is happening in the two images?
Left - infarct
Right - reperfusion injury (d/t damaged vessel wall, they become leaky & you can get hemorrhage in the surrounding area)
What pathology is shown in the provide image?
Acute Bland Infarct
12-48 hr
(w/o significant reperfusion injury)
What is the general cause of bland infarct vs. red infarcts?
- bland - in situ. thrombosis
- red - emboli
What is one of the earliest morphological findings of a bland infarct?
Edema & red neurons
clear spaces around red neurons that are starting to shrink
What is the first thing that moves into the space after an acute bland infarct?
Neutrophils
to break down tissue & clean up mess
What pathology is shown in the provided image?
This is at what time point after the initial injury?
Laminar necrosis after acute infarct (layered effect at grey/white junction)
48 hr - 10 days
The shown microscopic sample are from what larger pathology?
Why does this happen?
Lamina necrosis (acute infarct)
cortex is divided into different layers & some of those cells in different layers are more susceptible to ischemia than other layers
What do you see at 10-14 days after an infarct?
subacute infarct
phagocytosis of debris by macrophages & tissue begins to liquify
What pathlogy is shown in the provided image?
Remote infarct
> 2 weeks (years later)
neurons do not regenerat & you are left with a cavity
What pathology is shown in the provided image?
Remote infarct
> 2 weeks (years later)
neurons do not regenerat & you are left with a cavity filled with CSF
What are the effects of hypertension on the brain?
- lacunar infarcts
- slit hemorrhages
- acute hypertensive hemorrhages
- Charcot-Bouchard microaneurysm
- Acute hypertensive encephalopathy
What pathology is shown in the provided image?
What is a commonly underlying cause of this pathology?
Lacunar infarcts in the caudate & putamen
underlying cause - arteriosclerosis
What pathology is shown in the provided images?
Slit hemorrhages
What pathology is shown in the provided image?
Massive hypertensive hemorrhage with rupture iinto a lateral ventricle
What pathology is shown in the provided image?
Charcot-Bouchard Microaneurysm
small vessels (smaller than 250 microns)
What condition can result from malignat hypertension?
Acute hypertensive encephalopathy - medical emergency
fibrinoid necrosis
thromosis of arterioles & capillaries results in microinfarcts & microhemorrhages
What pathology is shown in the provided image?
Amyloid
- left
- congo red - light microscopy
- right
- congo red - polarized light
What pathology is shown in the provided image?
They are most commonly found where in the body?
“Berry” aneurysms
commonly found in circle of willis
Berry aneurysms typically affect what age group?
young adults (20s, 30s, 40s)
What do you see at a microscopic level in Berry aneurysms?
hyalinzed fibrosis (weaker than native vessel from which it arose)
What is the problem with arteriovenous malformations?
- Do not have large capillary bed in between arteries & veins
- veins become arteriolized because they are exposed to very high pressure - can be hard to differentiate arteris from veins
- have a propensity to bleed
What is a subarachnoid hemorrhage?
hemorrhage unde the arachnoid mater; may diffusely cover the brain
frequently fatal
What are the common causes of subarachnoid hemorrhages?
secondary to rupture of berry aneurysms
A-V malformation
What pathology is shown in the provided image?
Subarachnoid hemorrhage
looks like you need to “wash it off” but you cannot
What pathology is shown in the provided images?
Cavernous hemangioma (venous malformation)
typically focal; often asymptomatic
