radiopedia

Question 1

What is the most common tumor of the conus medullaris and filum terminale?

Answer 1

spinal myopapillary ependymomas

Question 2

myopapillary ependymomas occurs predominantly in what gender and at what age?

Answer 2

males, 35 yo

Question 3

How do myopapillary ependymomas present?

Answer 3

low back/leg/sacral pain +/- leg weakness and sphincter dysfunction

Question 4

myopapillary ependymomas… Is the lesion intradural or extradural? Intramedullary or extramedullary?

Answer 4

intradural/extramedullary

Question 5

What is the typical grade for myopapillary ependymomas?

Answer 5

WHO grade 1

Question 6

What is the microscopic appearance of myopapillary ependymomas?

Answer 6

perivascular pseudorosettes +/- rounded eosinophilic PAS + structures

Question 7

myopapillary ependymomas has positive immunostaining for?

Answer 7

GFAP, S100, vimentin

Question 8

How do myopapillary ependymomas appear on MRI?

Answer 8

at the conus medullaris or filum terminale; T1 isointense, T2 hyperintense, enhances with contrast

Question 9

Treatment and prognosis of myopapillary ependymomas

Answer 9

slow growing, usually resectable, 98% 5 year survival/good prognosis

Question 10

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?

Answer 10

medulloblastoma

Question 11

What is the most common primary brain tumor of childhood?

Answer 11

pilocystic astrocytoma

Question 12

pilocystic astrocytoma is associated with what genetic disease?

Answer 12

NF1, especially if it is an optic pathway glioma

Question 13

What is the most common location of a pilocystic astrocytoma?

Answer 13

cerebellum

Question 14

What is the microscopic appearance of pilocystic astrocytoma?

Answer 14

elongated hair-like projections; +eosinophilic Rosenthal fibers

Question 15

pilocystic astrocytoma is positive for what immunostaining?

Answer 15

GFAP, S100, OLIG2

Question 16

how do pilocystic astrocytomas appear on MRI?

Answer 16

large cystic component with brightly enhancing mural nodule

Question 17

most common location for an ependymoma?

Answer 17

60% in the posterior fossa

Question 18

A lobulated near-CSF intensity cerebellopontine angle mass with high signal on DWI is characteristic of?

Answer 18

an epidermoid cyst

Question 19

vividly enhancing masses in the region of the foramen of Monro in the context of tuberous sclerosis.

Answer 19

Subependymal giant cell astrocytomas (SEGA)

Question 20

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%.

Answer 20

Subependymomas

Question 21

Most common location of ependymomas by age?

Answer 21

adults: most often (70%) occur in the fourth ventricle
children: most often occur in the lateral ventricles,

Question 22

MRI appearance of primary CNS lymphoma?

Answer 22

homogenous enhancement and restricted diffusion. Usually supratentorial. No vasogenic edema or central necrosis (unless patient is immunocompromised)

Question 23

What happens if you treat primary CNS lymphoma with steroids prior to biopsy?

Answer 23

prevents diagnosis in 50% of cases due to shrinkage of tumor

Question 24

How does primary CNS lymphoma present?

Answer 24

increased ICP, FND, seizures

Question 25

Typical location of primary CNS lymphoma?

Answer 25

supratentorial

Question 26

What is the histological appearance of primary CNS lymphoma?

Answer 26

large quantities of lymphocytes (B-cells), +/- perivascular distribution

Question 27

What is found in CSF in patients with primary CNS lymphoma?

Answer 27

increased protein, decreased glucose, +cytology in 25% of cases

Question 28

What is the treatment of primary CNS lymphoma?

Answer 28

steroids, chemo with methotrexate, +/- radiation

Question 29

Prognosis of primary CNS lymphoma?

Answer 29

poor