Neuro Flashcards Preview

Pathology > Neuro > Flashcards

Flashcards in Neuro Deck (229)
Loading flashcards...
121

Pilocytic Astrocytoma

  • kids and young adults.
  • benign tumor in cerebellum, floor and walls of 3rd ventricle, optic nerve, cerebral hemispheres.
  • usually a p53 mutation.
  • morphology: grade I/IV tumor.  cystic with mural nodule in wall of cyst.
    • bipolar cells with long, thin, hairlike processes.
    • Rosenthal fibers and microcysts.
    • narrow infiltrative border surrounding brain.

122

Inflitrating Astrocytomas

  • 80% of adult primary brain tumors.
  • age: 30-60 yr.
  • low grade: overexpress PDGF-alpha and receptor.  mutated p53 function.
  • high grade: mutation of RB, p16/CDKNaA ⇒ activate RAS and PI-3 kinase pathways, inactivate RB and p53
  • morphology: grades II-IV.
  • presentation: focal neurologic deficits, headaches, seizures, from mass effects or cerebral edema.
    • high grade have contrast enhancement on imaging.

123

Diffuse Astrocytomas

  • infiltrating astrocytoma
  • grade II/IV
  • poorly defined, gray-white.  expands and distorts a region of the brain.
  • hypercellularity and nuclear pleomorphism
  • indistinct transition from normal to neoplastic

124

Anaplastic Astrocytoma

  • infiltrating astrocytoma
  • grade III/IV.
  • ↑ nuclear anaplasia with numerous mitoses.

125

Glioblastomas

  • infiltrating astrocytoma
  • grade IV/IV.
  • mixture of firm white areas, soft yellow areas of necrosis, cystic change, and hemorrhage.
  • ↑ vascularity

  • pseudopalisading = ↑ tumor cell density along necrotic edges.

  • poor prognosis, typically survive about 15 months.

126

Pleomorphic Xanthoastrocytomas

  • temporal lobes of young patients with history of seizures.
  • grade II/IV.
  • neoplastic bizarre astrocytes, abundant reticulin and lipid deposits, chronic inflammatory cell infiltrates.
  • 5 yr survival = 80%.

127

Brainstem Gliomas

  • ages 0-20yrs.
  • pontine is most common, aggressive.
  • tecta are benign.
  • corticomedullary junction = intermediate.

128

Oligodendroglioma

  • 5-15% of gliomas.
  • in mid life.
  • usually loss of heterozygosity in chromosomes 1p and 19q.
  • morphology: in white matter.  well circumscribed, gelatinous, gray masses with cysts, focal hemorrhage, and calcification.
    • sheets of regular cells with round nuclei containing finely granular chromatin surrounded by halo of cytoplasm.  sit in delicate capillary network.
    • calcification in 90%.
  • presentation: better prognosis than astrocytomas.  only have 1p 19q respond well to chemo and radiation.
    • survival 5-10 yrs
    • anaplastic = grade III/IV, worse prognosis.

129

Ependymoma

  • tumor arising from ependymal lining.
  • ages 0-20yrs: usually in 4th ventricle.
  • spinal cord central canal = middle age and neurofibromatosis type II.
  • morphology: moderately well-demarcated solid or papillary lesions.
    • round-oval nuclei with abundant granular chromatin.
    • form elongated ependymal canals or pervascular pseudorosettes.
    • grade II/IV.  
    • anaplastic = grade III/IV.  have ↑ cell density, mitoses, necrosis with less evident ependymal differentiation.
  • presentation: posterior fossa ependymomas have hydrocephalus.  CSF dissemination common.  
    • 50% 5 yr survival.
    • spinal cord lesions do better

130

Myxopapillary Ependymoma

  • arises in filum terminale of spinal cord.
  • cuboidal cells, can have clear cytoplasm, around papillary core.
  • myxoid areas have neutral and acidic mucopolysaccharides

131

Subependymoma

  • solid, calcified, slow growing nodules attached to ventricular lining, protruding into ventricle.
  • usually asymptomatic, can cause hydrocephalus.
  • morphology: clumps of ependymal-appearing nuclei scattered in dense, finely fibrillar background

132

Choroid Plexus Papilloma

  • recapitulate normal choroid plexus.
  • CT papillae covered with cuboidal-columnar ciliated epithelium.
  • hydrocephalus from obstruction or CSF overproduction.

133

Choroid Plexus Carcinoma

  • rare adenocarcinoma.
  • usually in kids

134

Colloid Cysts of 3rd Ventricle

  • non-neoplastic lesion in young adult.
  • in foramen of Monro.
  • noncommunicating hydrocephalus.  can be fatal.
  • contains gelatinous, proteinaceous material in a thin fibrous capsule lined by cuboidal epithelium.

135

Ganglioglioma

  • most common CNS tumor of mature-appearing neurons (ganglion cells).
  • slow growing even if aggressive.
  • morphology: in temporal lobe, cystic component.
    • neoplastic ganglion cells irregularly clustered, randomly oriented neurites.
    • glial component resembles low grade astrocytoma without necrosis/mitotic activity.
  • presentation: seizures that remit after resection.

136

Dysembryoplastic Neuroepithelial Tumor

  • rare, low grade childhood neoplasm.
  • morphology: intracortical location, cystic changes, nodular growth, 'floating neurons' in mucopolysaccharide rich fluid, surrounding neoplastic glia without anapastic features.
  • presentation: seizure disorder.
    • good prognosis with resection.

137

Central Neurocytoma

  • low grade neuronal neoplasm in ventricles.
  • evenly spaced, round, uniform nuclei and islands of neuropil.

138

Medulloblastoma

  • 20% childhood brain tumors.
  • in cerebellum.
  • loss of material from 17p with isochromosome of 17q.
  • MYC amplification = more aggressive.
  • ↑ neurotropin receptor TRKC or ↑ intranuclear beta-catenin = better outcome.

  • morphology: well circumscribed, gray and friable

    • extremely cellular, has sheets of anaplastic cells with hyperchromatic nuclei and abundant mitoses.

    • little cytoplasm, devoid of differentiation markers.  can have glial and neuronal features.

    • prominent desmoplasia if extend into subarachnoid space.

  • presentation: midline lesion in kids, lateral in adults.

    • rapid growth ⇒ occlude CSF flow, hydrocephalus.

    • CSF dissemination

    • highly malignant, poor prognosis untreated.

    • with excision and radiation have 75% 5 yr survival.

139

Atypical Teratoid/Rhabdoid Tumor

  • highly malignant tumor in posterior fossa and supratentorium of young kids.
  • survive <1yr.
  • chromosome 22 deletions.  hSNF5/INI1 that encodes protein in chromatin remodeling.
  • large, soft tumor over brain surface.
  • highly mitotic lesion with rhabdoid cells resembling rhabdomyosarcoma.

140

Primary Central Nervous System Lymphoma

  • 2% of extranodal lymphomas, 1% intracranial tumors.
  • most common CNS neoplasm in immunocompromised.
  • multifocal within CNS.  outside metastasis is late complication.
  • B-cell origin, infected with EBV
  • aggressive, respond poorly to chemo
  • morphology: diffuse large-cell B-cell lymphoma.
    • involve parenchyma of brain, see around blood vessels.

141

Germ Cell Tumors

  • along midline in adolescents and young adults.
  • 0.2-1% caucasian CNS tumors, 10% Japanese
  • in pineal gland (men) and suprasellar regions.

142

Meningioma

  • benign tumor of adult coming from arachnoid meningothelial cells, are attached to dura.
  • loss of heterozygosity of long arm of chromosome 22.  NF2 gene (merlin protein).
  • morphology: rounded masses with well-defined dural bases compress brain but can separate it.
    • firm, lack necrosis or extensive hemorrhage.
    • gritty from calcified psammoma bodies.
    • patterns = synctytial, fibroblastic, transitional, psammomatous, secretory, and microcystic.  grade I/IV.
    • proliferative index predicts behavior.
  • presentation: solitary, slow growing lesion. manifest from CNS compression or vague non-localizing symptoms.
    • uncommon in kids.  
    • 3:2 f:m.  express progesterone receptors, grow faster during pregnancy.

143

Anaplastic Meningioma

  • grade III/IV.
  • aggressive, resemble sarcomas.
  • high mitotic rates

144

Papillary Meningioma

  • pleomorphic cells arranged around fibrovascular cores.
  • grade III/IV

145

Rhabdoid Meningioma

  • sheets of cells with hyaline eosinophilic cytoplasms composed of intermediate filaments.
  • grade III/IV.
  • high recurrence rate.

146

Tumors Metastatic to Brain

  • 50% intracranial tumors.
  • primary sites: lungs, breast, skin (melanoma), kidney, and GI tract.
  • can also come from meninges.
  • morphology: sharply demarcated, at gray-white junction.  surrounded by edema.
    • meningeal carcinomatosis = tumor nodules studding brain surface, spinal cord, and nerve roots.
      • see in lung and breast carcinomas.

147

Subacute Cerebellar Degeneration

  • most common paraneoplastic syndrome.
  • have Purkinje cell loss, gliosis, and inflammatory infiltrates.

148

Paraneoplastic Syndromes

  • from malignancy elsewhere.
  • due to anti-tumor immune responses cross reacting with CNS and PNS antigens.
  • subacute cerebellar degeneration, limbic encephalitis, eye movement disorders, subacute sensory neuropathy, Lambert-Eaton myasthenic syndrome.

149

Limbic Encephalitis

  • paraneoplastic syndrome.
  • subacute dementia associated with perivascular inflammation, microglial nodules, neuronal loss, and gliosis.
  • anterior and medial temporal lobes.

150

Eye Movement Disorders

  • paraneoplastic syndrome.
  • associated with childhood neuroblastomas.