radiopedia Flashcards
What is the most common tumor of the conus medullaris and filum terminale?
spinal myopapillary ependymomas
myopapillary ependymomas occurs predominantly in what gender and at what age?
males, 35 yo
How do myopapillary ependymomas present?
low back/leg/sacral pain +/- leg weakness and sphincter dysfunction
myopapillary ependymomas… Is the lesion intradural or extradural? Intramedullary or extramedullary?
intradural/extramedullary
What is the typical grade for myopapillary ependymomas?
WHO grade 1
What is the microscopic appearance of myopapillary ependymomas?
perivascular pseudorosettes +/- rounded eosinophilic PAS + structures
myopapillary ependymomas has positive immunostaining for?
GFAP, S100, vimentin
How do myopapillary ependymomas appear on MRI?
at the conus medullaris or filum terminale; T1 isointense, T2 hyperintense, enhances with contrast
Treatment and prognosis of myopapillary ependymomas
slow growing, usually resectable, 98% 5 year survival/good prognosis
Mass in the 4th ventricle. MRI T2 flair hetergenous due to calcification, necrosis, cyst formation. Presents with hydrocephalus. Histology: small round blue cell tumor. What tumor does this describe?
medulloblastoma
What is the most common primary brain tumor of childhood?
pilocystic astrocytoma
pilocystic astrocytoma is associated with what genetic disease?
NF1, especially if it is an optic pathway glioma
What is the most common location of a pilocystic astrocytoma?
cerebellum
What is the microscopic appearance of pilocystic astrocytoma?
elongated hair-like projections; +eosinophilic Rosenthal fibers
pilocystic astrocytoma is positive for what immunostaining?
GFAP, S100, OLIG2
how do pilocystic astrocytomas appear on MRI?
large cystic component with brightly enhancing mural nodule
most common location for an ependymoma?
60% in the posterior fossa
A lobulated near-CSF intensity cerebellopontine angle mass with high signal on DWI is characteristic of?
an epidermoid cyst
vividly enhancing masses in the region of the foramen of Monro in the context of tuberous sclerosis.
Subependymal giant cell astrocytomas (SEGA)
tend to present in middle-aged to older individuals and are most commonly seen in the fourth ventricle (50-60%) and lateral ventricles (usually frontal horns): 30-40%.
Subependymomas
Most common location of ependymomas by age?
adults: most often (70%) occur in the fourth ventricle
children: most often occur in the lateral ventricles,
MRI appearance of primary CNS lymphoma?
homogenous enhancement and restricted diffusion. Usually supratentorial. No vasogenic edema or central necrosis (unless patient is immunocompromised)
What happens if you treat primary CNS lymphoma with steroids prior to biopsy?
prevents diagnosis in 50% of cases due to shrinkage of tumor
How does primary CNS lymphoma present?
increased ICP, FND, seizures
Typical location of primary CNS lymphoma?
supratentorial
What is the histological appearance of primary CNS lymphoma?
large quantities of lymphocytes (B-cells), +/- perivascular distribution
What is found in CSF in patients with primary CNS lymphoma?
increased protein, decreased glucose, +cytology in 25% of cases
What is the treatment of primary CNS lymphoma?
steroids, chemo with methotrexate, +/- radiation
Prognosis of primary CNS lymphoma?
poor
