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.
- bipolar cells with long, thin, hairlike processes.
- Rosenthal fibers and microcysts.
- narrow infiltrative border surrounding brain.
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.
- high grade have contrast enhancement on imaging.
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
Anaplastic Astrocytoma
- infiltrating astrocytoma
-
grade III/IV.
-
↑ nuclear anaplasia with numerous mitoses.
↑ nuclear anaplasia with numerous mitoses.
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.
↑ vascularity
pseudopalisading = ↑ tumor cell density along necrotic edges.
poor prognosis, typically survive about 15 months.
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%.
Brainstem Gliomas
- ages 0-20yrs.
-
pontine is most common, aggressive.
-
tecta are benign.
-
corticomedullary junction = intermediate.
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.
- sheets of regular cells with round nuclei containing finely granular chromatin surrounded by halo of cytoplasm. sit in delicate capillary network.
- calcification in 90%.
- survival 5-10 yrs
- anaplastic = grade III/IV, worse prognosis.
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
- 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.
- 50% 5 yr survival.
- spinal cord lesions do better
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
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
Choroid Plexus Papilloma
- recapitulate normal choroid plexus.
-
CT papillae covered with cuboidal-columnar ciliated epithelium.
-
hydrocephalus from obstruction or CSF overproduction.
Choroid Plexus Carcinoma
- rare adenocarcinoma.
- usually in kids
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.
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.
- neoplastic ganglion cells irregularly clustered, randomly oriented neurites.
- glial component resembles low grade astrocytoma without necrosis/mitotic activity.
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.
- good prognosis with resection.
Central Neurocytoma
-
low grade neuronal neoplasm in ventricles.
-
evenly spaced, round, uniform nuclei and islands of neuropil.
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.
↑ 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.
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.
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.
- involve parenchyma of brain, see around blood vessels.
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.
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.
- 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.
- uncommon in kids.
- 3:2 f:m. express progesterone receptors, grow faster during pregnancy.
Anaplastic Meningioma
-
grade III/IV.
-
aggressive, resemble sarcomas.
- high mitotic rates
Papillary Meningioma
-
pleomorphic cells arranged around fibrovascular cores.
-
grade III/IV
Rhabdoid Meningioma
-
sheets of cells with hyaline eosinophilic cytoplasms composed of intermediate filaments.
-
grade III/IV.
- high recurrence rate.
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.
-
meningeal carcinomatosis = tumor nodules studding brain surface, spinal cord, and nerve roots.
- see in lung and breast carcinomas.
Subacute Cerebellar Degeneration
-
most common paraneoplastic syndrome.
- have Purkinje cell loss, gliosis, and inflammatory infiltrates.
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.
Limbic Encephalitis
- paraneoplastic syndrome.
-
subacute dementia associated with perivascular inflammation, microglial nodules, neuronal loss, and gliosis.
-
anterior and medial temporal lobes.
Eye Movement Disorders