030415 brain tumors Flashcards
types of primary brain tumors
meningiomas
gliomas: astrocytomas, glioblastoma, ependymoma, oligodendroglioma, embryonal tumors
others: pituitary, nerve sheath tumors, lymphoma, craniopharyngioma, germ cell tumors, etc
morbidity and mortality in low and high grade neoplasms in CNS
both low and high have significant morbidity and mortality (diffusely infiltrative, involvement of critical anatomic areas, inability to resect critical anatomic areas)
astrocytomas
most common glial tumor
diffuse astrocytomas (grade 2) have tendency to progress to higher grades (anaplastic astrocytoma, glioblastoma) over time
80% are glioblastomas
clinical features of astrocytomas
seizures
focal neurologic deficits (GRADUAL onset)
headaches
median survival for glioblastoma multiforme
1 yr
WHO grading scheme for astrocytomas
1: pilocytic astrocytoma (no tendency to become higher grade)
2: astrocytoma (diffuse)–CELLULARITY is moderately increased and occasional NUCLEAR ATYPIA
3: anaplastic astrocytoma–increased cellularity, distinct nuclear atypia, marked MITOTIC ACTIVITY
4: glioblastoma multiforme–pleomorphic astrocytic cells, brisk mitotic activity, prominent MICROVASCULAR PROLIFERATION AND NECROSIS
grade 2 astrocytoma-gross morphoogy
flattened gyri, ill-defined
necrosis w pseudopalisading
distinct for grade 4 astrocytoma
pilocytic astrocytoma occurs where
most commonly cerebellum
imaging of pilocytic astrocytoma
well demarcated
cystic tumor w/ enhancing mural nodule
histology of pilocytic astrocytoma
densely fibrillary (pilocytic/hair like) areas alternating w microcystic component
Rosenthal fibers (eosinophilic astrocyte processes)
oligodendroglioma occurs in whom
adults
imaging of oligodendroglioma
well defined hypodense mass, may see CALCIFICATION
prognosis for oligodendroglioma
5-10 yrs for grade II
better than for astrocytomas
allelic loss of chromosome 1p and 19q are predictors of prolonged survival and susceptiblity to chemo
anaplastic oligodendrogliomas
histology of oligodendroglioma
calcifications
round nuclei, “FRIED EGG” cells
ependymoma occurs in whom
usually children
prognosis for ependymoma
4 yrs
histology of ependymoma
true rosettes (mini ventricle) perivascular pseudorosettes
choroid plexus papilloma occurs in whom
kids
where does choroid plexus papilloma occur
4th ventricle, lateral ventricle, 3rd ventricle, cerebellopontine angle
prognosis for choroid plexus papilloma
very good w surgical resection if papilloma
if carcinoma, poor prognosis
colloid cyst
benign
usually attached to roof of 3rd ventricle
can obstruct foramen of Munro intermittently
positional headache
ganglioglioma occurs in whom
young (under 30)
where does ganglioma occur
typically supratentorial and in temporal lobe
how is ganglioglioma like or unlike pilocytic astrocytoma
it also has cyst w mural nodule, but it’s in cerebrum
medulloblastoma
embryonal neuroepithelial neoplasm of POSTERIOR FOSSA, of primitive neuroectoderm
characteristic feature of medulloblastoma
tendency to spread through CSF pathways
tx for medulloblastoma
surgical resection followed by radiation (usually cranio-spinal)
histology for medulloblastoma
small blue cells, highly cellular
Homer Wright rosettes
primary CNS lymphoma
occur btwn 40-60
poor prognosis-most die within a year
periventricular lesions
meningioma
extra parenchymal tumor of CNS
women more than men
imaging of meningioma
DURAL BASED
WELL DEFINED
meningioma-associations
progesterone receptors
NF2, radiotherapy
outlook for meningioma
if grade I, excellent 5 yr survival
histology for meningioma
sheets of tumor cells w indistinct borders
whorls
Psammoma bodies
where are schwannomas located usually
peripheral nerves in head and neck and flexor surfaces or extremities
schwannomas-intracranial tumors most often in cerebellopontine angle and attached to 8th nerve (symptoms of hearing loss, tinnitis, facial numbness)
neurofibroma
benign tumor composed of Schwann cells, fibroblasts, perineural cells
assoc w NF1
cutaneous form and peripheral nerve form
familial tumor syndromes assoc w increased risk of nervous system tumors-four types
NF1, NF2, Von Hippel LIndau dis, tuberous sclerosis
each has cutneaous or eye abnormalities
most linked to loss of tumor suppressor genes
NF1
much more common than NF2
neurofibromas, cafe au lait spots, Lisch nodules, optic glioma, oseeous lesions, axillary freckling, family hx
associated tumors: MOST IMPORTANT-NEUROFIBROMAS THAT UNDERGO TRANSFORMATION TO MALIGNANT PERIPHERAL NERVE SHEATH TUMORS
NF2
criteria include: BILATERAL VESTIBULAR SCHWANNOMAS (most common manifestation), first degree relative w NF2, lens opacity, cerebral calcifications
other associations: meningiomas, schwannomas, gliomas, neurofibromas
Von Hippel Lindau dis
hemangioblastomas of CNS and retina (CEREBELLAR HEMANGIOBLASTOMAS)
renal cell carcinoma, pheo, visceral cysts, retinal angiomas
tuberous sclerosis
clinical: SEIZURES, autism, cognitive dysfxn
CORTICAL HAMARTOMAS (TUBERS-neuronal and glial properties), subependymal giant cell astrocytomas, etc
paraneoplastic syndrome
clinical syndrome produced by remote effect of systemic malignancy
hypothesized that some visceral cancers express certain neural antigens. immune system recognizes these antigens as foreign and attacks own CNS/PNS
Lambert Eaton myasthenic syndrome
paraneoplastic neurologic syndrome
muscle weakness esp in legs that improves w testing on exam
metastatic tumor in brain–what to tx w?
radiation therapy
