neuropath Flashcards
Neuron. Large perikaryon; lots of nissl substance (RER), but abscent at axon hillock; large nucleus with prominant nucleolus and dispersed chromatin
Astrocyte. Glial cell; major function is to wrap foot processes around the basement membrane of blood vessels and non-synaptic parts of neurons–nutrient exchange; short and highly branched in gray matter, sparse and straighter in white matter.
astrocyte stained for GFAP
(cells around neuron)
oligodendrocytes; myelinate CNS; smalelr, rounder, darker nucleus than astro; 2-3 normally found around neuron (excess is perineuronal satellitosis)
ependymal cells. glial-derived epithelium lining ventricles and spinal canal. no basement membrane. absorptive/secretory/propulsive functions
choroid plexus. gilal-derived secretory epithelium; long microvilli with few cells. many mitochondria, golgi, and basal nuclei
red neurons. response to ischemic injury (12-24 hrs). shrunken soma, eosinophilia, loss of Nissl. nuclei often darker w/o nucleolus.
lipofuscin. normal age-related process of oxidized fatty acid accumulation. don’t confuse with SN, DMX, or locus ceruleus of rostral pons (pigmented areas)
flame-shaped cytoplasmic inclusions = neurofibrillary tangle in AD
Lewy Body inclusions
early abcess: PMN infiltration
late abcess: PMN debris surrounded by fibroblastic collagenous
Acid-fast stain shows TB organisms
microglial nodules (acute viral encephalitis)
intranuclear inclusions (acute viral encephalitis)
microglial nodule and neuronophagia (acute viral encephalitis)
perivascular infiltrate (actue viral encephalitis)
aseptic meningitis
Negri bodies (circumscribed eosinophilic cytoplasmic inclusions). Rabies
cysticercosis (taenia solium). from ingesting eggs. Parenchymal, meningeal, ventricular, spinal (rare) cysts
naegleria fowleri. Primary amebic encephalitis. Fulminant, acute meningoencephalitis with swelling, hemorrhagic necrossis of frontal lobes. Path: unicellular organisms with vesicular nucleus in subarachnoid space
zygomycosis (mucor). Classically DKA, rhinocerebral disease. wider, non-septate hyphae
silver stain of aspergillus (thin, branching hyphae). Infiltrate blood vessels, causing vasculat thrombosis, hemorrhage, infarct with variable inflamm infiltrate. multiple lesions, early resemble hemorrhagic infarct, form abscesses, rarely fibrous ca[sule.
Direct seeding of cranial cavity results in chronic, localized ingection with fibrosis/granuloma
diffuse astrocytoma. scattered, pleomorphic, angulated, hypochromatic nuclei w/o mitoses
gemistocytic variant diffuse astrocytoma (grade II). plump cells with glassy cytoplasm
anaplastic astrocytoma (grade III): atypia + mitoses. foci of increased density/pleomorphism
(tumor type and genetics)
glioblastoma (grade IV astrocytoma): high cellularity, atypia, mitoses, areas of necrosis and neovascularization.
IDH 1/2 = 2ndry GBM. IDH 1 = better prognosis
EGFR = probably primary
TP53 = probably secondary
(tumor type and genetics)
spony-cystic type pilocytic astrocytoma (non-infiltrating).
7q34 BRAF fusion
(tumor type and genetics)
compact type pilocytic astrocytoma (non-infiltrating) with Rosenthal fibers
7q34 BRAF fusion
homer wright rosettes (medulloblastoma–differentiated)
dense round/ovoid nuceli = medullablastoma
pseudorosettes surrounding blood vessels = ependymoma
ependymoma
fried egg + chicken wire = oligodendroglioma
whorls with psammoma bodies = psammomatous meningioma
whorls and cords = transitional meningioma
