Neuroscience Week 5: Tumors of the CNS Flashcards
What % of tumors are supratentorial?
- 80% of adult tumors are supratentorial
- 80% of pediatric tumors are infratentorial

Intra-axial vs extra-axial tumors
- Extra-axial tumors are well demarcated and have a better prognosis
- Infiltrating tumors are rarely cured
Mass effect of neoplasms in the CNS
- Headache
- focal symptoms
- herniation
Infiltrating tumors can cause ___________ depending on location and also ___________.
- focal symptoms
- Seizures
Clinical presentations of CNS neoplasms non-focal
- head-ache
- seizures
Clinical presentations of CNS neoplasms focal
- motor
- sensory
- cerebellar
- seizure
- etc.
Types of herniations
- cingulate herniation
- transtentorial herniation
- Uncal herniation
- Cerebellar tonsilar herniation

Types of hydrocephalus

Main Types of CNS tumors
5 listed

Astrocytoma tumor type
Glioma
Most common type of glioma
Astrocytoma (>70% of gliomas)
Grades of Astrocytoma
4 listed

Pilocytic Astrocytoma grade
WHO grade 1
Pilocytic Astrocytoma age of onset
most common primary tumor in childhood
The most common primary tumor in childhood
Pilocytic Astrocytoma
Pilocytic Astrocytoma common location
common in cerebellum (also hypothalamus and optic chiasm)
Pilocytic Astrocytoma gross appearance
circumscribed and often cystic with a solid mural nodule

Pilocytic Astrocytoma Histological features and histological markers
- Cells of origin are GFAP positive
- biphasic pattern consisting of cellular and fibrillary perivascular areas, alternating with loose microcystic zones
- The tumor cells often contain Rosenthal fibers and eosinophilic granular bodies. Pilocytic (hair cell) refers to the fiber-like appearance of the tumor cells

Pilocytic Astrocytoma prognosis
- excellent
- because surgically resectable
Diffuse Astrocytoma Grade
WHO Grade 2

Diffuse Astrocytoma age of onset
most frequent in young adults
Diffuse Astrocytoma location
most frequent in the cerebral hemispheres, especially the frontal lobes
Diffuse Astrocytoma gross appearance
- poorly demarcated
- produce an enlargement of the involved portion of the brain and blurring of anatomical landmarks
Diffuse Astrocytoma Histological features
low grade cellularity and pleomorphism but no atypia or mitoses
Diffuse Astrocytoma Growth rate
very slowly over several years
Diffuse Astrocytoma prognosis
depends on how long the tumor has grown
Anaplastic Astrocytoma Grade
WHO Grade 3
Anaplastic Astrocytoma histological features
- has intermediate characteristics between grade 2 and glioblastoma
- can originate on a grade 2 tumor or appear de novo
- it is more cellular and has more prominent atypia and a higher mitotic rate

Anaplastic Astrocytoma growth rate
more rapidly growing

Anaplastic Astrocytoma prognosis
3-5 year survival
Glioblastoma Grade
WHO Grade 4
Glioblastoma Age of onset
common in middle-aged and older adults

Glioblastoma common location
common in frontal and temporal lobes
can cross the corpus callosum (butterfly glioma)

Butterfly glioma
a glioblastoma that crosses the corpus callosum

Glioblastoma can be ________ or _________ to a ____________.
Glioblastoma can be primary or secondary to a lower grade astrocytoma.
Glioblastoma Prognosis
Very aggressive tumor with a short survival (1 year)
Glioblastoma gross appearance
present as poorly defined intra-axial masses with multiform appearance due to necrosis and hemorrhage

Glioblastoma Histological features
- pseudopalisading with central necrosis, anaphasia and vascular proliferation.
- cellular anaplasia (pleomorphism) in large cell glioblastoma
- Glioblastoma
- vascular endothelial proliferation

Oligodendroglioma tumor type
Gliomas
Oligodendroglioma description
Malignant tumors derived from oligodendrocytes

Oligodendroglioma age of onset
Adult

Oligodendroglioma common location
- supratentorial, often white matter
- the frontal lobes are commonly affected

Oligodendroglioma gross appearance
- well circumscribed (compared to astrocytoma)
- calcifications are common

Oligodendroglioma Histological Features
- Fried-egg cellular appearance (round nuclei and clear cytoplasm)
- chicken wire (or chicken feet) vessels

Oligodendroglioma Prognosis
somewhat better than astrocytoma

Ependymoma tumor type
Glioma
Ependymoma Description
Ependymal cells

Ependymoma common location
most commonly associated with the 4th ventricle

Ependymoma age of onset
- most commonly in children (infratentorial)
- rarely in adults but typically (supratentorial)

Ependymoma Gross appearance
- intraventricular
- well-circumscribed
- sometimes with calcification

Ependymoma Histological Features
key histological feature perivascular pseudorosettes and less commonly true ependymal rosettes

Ependymoma Prognosis
Largely dependent on the completeness of resection

Medulloblastoma Tumor type
Embryonal Neoplasms
Medulloblastoma description
primitive neuroectoderm tumor
Medulloblastoma common location
typically arise in the midline cerebellum

Medulloblastoma age of onset
- Is the most common childhood tumor
- usually present in children
- very rare in (>20)
Medulloblastoma common location
- Typically arise in the midline cerebellum
- can compress the 4th ventricle causing non-communicating hydrocephalus

Medulloblastoma Gross appearance
- solid and enhancing most common
- infiltrates the cerebellum

Medulloblastoma Histological Features
- Small blue cell tumor
- Homer-Wright Rosettes (no true lumen)

Medulloblastoma Prognosis
- although malignant, they are responsive to radiotherapy and chemotherapy and can sometimes be cured
- the issue is that they spread through CSF pathways (drop metastases in subarachnoid space and neuraxis treatment may be necessary)

Small blue cell tumor description
embryonal tumors with closely packed cells with little cytoplasm

Pituitary Adenoma tumor type
Tumors of the Sella region
Pituitary Adenoma description and common presentation
- can be silent or functioning (can produce hormones)
- Prolactinoma is the most common (lactotrophs)
Pituitary Adenoma types
5 listed
- Lactotrophs (prolactin)
- somatotrophs (Growth hormone)
- corticotrophs (ACTH)
- tyrotrophs (Thyroid stimulating hormone)
- gonadotrophs (gonadotropins)

Pituitary Adenoma common clinical presentation
- bitemporal hemianopsia
- endocrine abnormalities
- headaches

Pituitary Adenoma Histological Features
shows hyperplasia of one type of cell (e.g. lactotrophs)

Craniopharyngioma age of onset
most commonly found in children and adolescents
Craniopharyngioma can be confused with?
Pituitary adenoma (both cause bitemporal hemianopsia)

Craniopharyngioma derived from?
remnants of Ratke Pouch (ectoderm)

Craniopharyngioma Histological features
- Islands of keratin often calcify
- often cystic changes
- cholesterol crystals float in the greasy fluid that fills the cysts
- all of this is embedded in an island of neural tissue

Primary CNS Lymphoma derivation
Microglia or rare lymphocytes present in meninges and around blood vessels

Primary CNS Lymphoma age of onset
rare tumor that occurs more commonly in immunocompromised patients
Primary CNS Lymphoma cells are usually positive for
EBV
Primary CNS Lymphoma common locations
most cases are supratentorial
Primary CNS Lymphoma Histological features
- Dense perivascular sheets or diffuse masses
- Usually positive for EBV

Primary CNS Lymphoma Prognosis
- aggressive tumors with poor response to chemotherapy (as opposed to peripheral lymphomas)

Meningioma derivation
Arachnoid cells
Meningioma Age of onset
- 15% of all CNS tumors (25% are spinal)
- More common in women
Meningioma Gross appearance
- Extra-axial and well-circumscribed (may have dural attachment; dural tail)
- enhancing (external carotid blood supply)
Meningioma Common Locations
- Parasagittal
- falx
- lateral convexity
- sphenoid ridge
- olfactory groove
- posterior fossa
- spinal canal

Meningioma histological patterns
3 listed
- Transitional with whorls
- Fibroblastic
- Psammatous
Meningioma Histological Features
- Meningothelial
- fibroblastic
- Psammomatous (grain of sand-like) and others
- whorls such as in the transition meningioma
- radiating pattern such as in the fibroblastic meningioma

CNS Metastasis derivation
Usually similar in histology to the primary tumor

CNS Metastasis common locations
- originate at gray-white junctions
- often present at multiple lesions

CNS Metastasis age of onset
5-25% of people with malignant tumors will develop CNS metastases

CNS Metastasis common primary sites
- lung
- breast
- melanoma
- renal cell carcinoma
- colon cancer
- Choriocarcinoma in younger patients

CNS Metastasis Gross appearance
usually parenchymal in brain - may be bone associated in spine often enhancing and circumscribed

CNS Metastasis Histological features
Usually correlated with the primary malignancy

CNS Metastasis Prognosis
Bad, may depend on systemic control of disease

Familial tumor syndromes
3 listed
- Tuberous Sclerosis
- Von Hippel-Lindau Disease
- Neurofibromatosis type I and II
Optic Nerve Glioma is associated with?
Neurofibromatosis Type I
Acoustic Schwannomas are associated with?
2 listed
Neurofibromatosis Type II
&
Lateral pontine syndrome
Meningiomas are associated with this(ese) neurocutaneous disorders
2 listed
- Neurofibromatosis Type II
- Sturge-Weber (ipsilateral meningiomas)
Ependymomas in the spinal cord are associated with this(ese) neurocutaneous disorders
Neurofibromatosis Type II

Ipsilateral Meningiomas are associated with this(ese) neurocutaneous disorders
Sturge-Weber
subependymal astrocytomas are associated with this(ese) neurocutaneous disorders
Tuberous Sclerosis

Hemanagioblastoma (cerebellum/retina) are associated with this(ese) neurocutaneous disorders
Von Hippel-Lindau

Schwannomas overview
- Cerebellopontine angle tumor
- hallmark of NF2
- fasicles of spindle cells and complete pallisading pattern
- S-100 Positive

Histological features: fascicles of spindle cells and complete palisading pattern
Schwannomas
Hemangioblastoma overview
- Von Hippel Lindau Disease
- Multiple (cerebellum, spinal cord, retina)
- Typically cerebellar hemangioblastoma is a mural nodule within a cyst
- Can produce erythropoietin

509 first aid

HAMARTOMAS can be present in
CNS in tuberous sclerosis
Adult tumors
510 and 511 images

Childhood tumors
- pg 512
- pinealoma (gaze palsy)

Common location of pilocytic astrocytoma
Cerebellum
but also
optic chiasm and hypothalamus
Diffuse astrocytoma most common location
common in the cerebral hemispheres and especially in the frontal lobes
Schwannoma cells are usually positive for?
S-100
histological features:
Small blue cell tumor
Homer-Wright Rosettes (no true lumen)
Medulloblastoma
may have dural attachment; dural tail
Meningioma