CNS tumors Flashcards
Most common primary benign brain tumor
Meningioma
What do glial cells do?
Surround neurons and provide support, insulation and nutrients
Most abundant cell type in CNS
Types of CNS glial cells
Astrocytes
Ependymal cells
Oligodendrocytes
Microglia
Where does an astrocytoma originate?
Astrocyte (main glial supporting cell in CNS)”
Types of astrocytomas
Diffuse (cannot be resected completely and grade by WHO into grade I-IV based on histology)
Circumscribed
How to classify diffusely infiltrating gliomas of astrocytic and oligodendroglial lineage
Based on 2 recurrent and favorable molecular prognostic factors:
IDH mutation
1p/19q codeletion
WHO classification of most astrocytomas
IDH mutant
WHO classification of most oligodendogliomas
Both IDH mutant AND 1p/19q codeletion
Subclassifications of glioblastomas
IDH wildtype (most and worst prognosis)
IDH mutated
Glioblastoma not otherwise specified (NOS)
Malignant astrocytic neoplasms (HIGH GRADE GLIOMAS) are divided into 2 main groups
(based on degree of hypercellularity, nuclear pleomorphism, mitoses, microvascular proliferation and necrosis)
- Anaplastic astrocytoma (AA, grade 3)
- Glioblastoma multiforme (GBM, grade 4)
Presentation of anaplastic astrocytoma and glioblatoma multiforme
Short history of HAs, seizures, focal neuro sxs based on location
Predilection of extend across corpus callous of to spread along other major white matter tracts (butterfly)
How do malignant gliomas look on MRI?
Irregular mass lesions, heterogeneous or ring enhancing
MRI presentation of anaplastic astrocytoma and glioblatoma multiforme
T2W/FLAIR: abnormal signal extending in irregular pattern with extension beyond margins of contrast enhancement (usually infiltrating tumor cells in that area)
Most common and deadly glioma in adults
Glioblastoma multiforme
How to confirm glioblastoma multiforme
Imaging can suggest it but must do pathologic confirmation by biopsy or surgical resection
If can’t do that (b/c brainstem glioma), then do MR spectroscopy
Standard therapy for high grade glioma
1- maximal tumor resection with preservation of neuro function
2- limited field radiation therapy with 2-3 cm margin around radiographically visible tumor area (maybe chemo too)
Techniques for aggressive resection
Awake craniotomy
Diffusion tensor imaging or stimulation mapping to ID subcortical motor pathways
Intraoperative MRI
Prognosis of high grade gliomas
Most recur despite aggressive tx (6-8 month tumor progression)
Chemotherapy is best suited for which type of anaplastic oligodendroglioma
Codeleted 1p/19q
Types of supportive care for high grade gliomas
Dexamethasome to reduce peri-tumor edema and increase neuro function Pain and depression tx Seizure therapy (non enzyme inducing antiepileptics)
Greatest prognostic factors in high grade gliomas
Pt age (>65 YO is worst)
Tumor histology
Pretreatment performance status
(median survival tho is 12-15 months)
How are low grade gliomas different from high grade?
Low tends to infiltrate rather than compress or destroy brain parencyma
How do most pts with low grade glioma present?
Seizures (can be partial)
Classification of most low grade gliomas
IDH mutations
Imaging of low grade gliomas
Poorly circumscribed lesions with diffuse infiltration
Hard to define gross and microscopic margins
What might help the diagnostic accuracy with low grade gliomas?
Tumor debulking
Which is more sensitive to chemo: oligodendrogliomas or astrocytomas
Oligodendrogliomas (has better prognosis too)
Where does oligodendroglioma originate?
Oligodendrocytes (produce myelin sheaths in CNS)
-low and high grade types
Classic histological features of oligodendrogliomas
Uniform round nuclei and clear perinuclear halos (fried egg) with network of branching capillaries (chicken wire)
Classification of most oligodendrogliomas
Most have 1p/19q co deletion (may also have TP53 mutation)
MRI for low grade astrocytoma
Poorly demarcated hypointense mass lesion on T1W images and hyperintense lesion on T2/FLAIR
GAD enhancement
Infiltration of tumor cells extends beyond margins or radiographically definable or grossly visible tumor
How does low grade oligodendroglioma look on MRI?
Ill defined non-enhancing lesion
High grade is heterogenous and ring enhacing
Tumor calcifications commonly seen
(cannot differentiate from astrocytic tumors solely with neuro imaging)
Younger pt with oligodendrogliomas and no neuro sxs
Defer surgery/RT (not negative impact if do so)
Why to prolong radiation as long as possible?
Can cause neurotoxicity
When to give radiation to pt with oligodendrogliomas?
Not candidate for aggressive tumor resecti on
Have large post op tumor burden
>50 YO at diagnosis
Indications of early intervention with oligodendroglioma and astrocytoma
Neuro sxs other than seizures
Presence of significant mass effect on imaging
Growth of lesion on serial scans
Age >50
Prognosis of astrocytoma
Survival supratentorial astrocytoma 5-9 ys
Age at onset is strong independent predictor of survival outcome
Negative impact if significant neuro deficit or >50 at diagnosis
Favorable prognosis with long history of seizures and no other deficits
What is present in most newly diagnosed low grade oligodendrogliomas
1p/q19 co deletion
Importance of 1p/q19 co deletion with oligodendroglioma
Independent prognostic marker for less aggressive behavior, better response to tx (chemo) and better overall survival
Where does meningioma come from?
Arachnoid cells
Presence of meningioma
Most asymptomatic (found on imaging or autopsy) Symptomatic twice as comon in women (estrogen and progesterone receptors on tumor)
Imaging for meningioma
Encircle on another, forming calcified whorls called psammoma bodies (solitary contrast enhancing lesions adjacent to dural surfaces)
Classification of meningiomas
Grade 1: most and best to have
Grade 2: atypical and diagnosis made on brain invasion
Grade 3: malignant/anaplastic
Common sites of origin for meningiomas
Cerebral convexity, parasagittal area, falx and sphenoid ridge
Presentation of meningioma
Slow growth with slow progression of sxs
Hyperostosis in skull adjacent to tumor and this bone usually invaded by tumor cells
Peritumor edema
Imaging for meningioma
MRA/MRV to determine blood supply in consideration for surgery or preop embolization
Can you use chemo for meningiomas?
Not sensitive
Therapy for meningioma
Defer tx until sxs develop or tumor enlarges
Symptomatic: total surgical resection with improved or preserved function
When to use radiation with meningiomas?
If symptomatic and not amenable to aggressive resection, significant residual tumor, recurrent tumor or newly diagnosed atypical or anaplastic meningioma
Most important prognostic factor of meningioma
Extent of initial resection and histological tumor grade (recurrence free survival in some after total resection)
When does outcome improve for meningioma and incomplete resection?
If post op radiation
What is primary CNS lymphoma?
Rare and aggressive extra nodal non hodgkin lymphoma
When do you see more primary CNS lymphomas?
HIV infection (EBV) and organ transplant recipients
How are most primary CNS lymphomas classified
Diffuse large cell B lymphoma
Presentation of primary CNS lymphoma
AMS and focal neuro sxs
Deficits progress rapidly and diagnose in 2-3 mos
Less seizures than with gliomas
Can have lymphomatous infiltration, leptomeningeal dissemination
What does primary CNS lymphoma have predilection for?
Deep or midline brain structures
MRI for primary CNS lymphoma
Multifocal lesions that are bright with homogenous contrast enhancement in half of pts
Therapy for primary CNS lymphoma
Corticosteroids reduce peritumoral edema and have direct oncolytic effect to have temporary improvement (steroids should be held prior to biopsy since it might make it nondiagnostic)
What is no longer recommended for newly diagnosed primary CNS lymphoma
Whole brain RT (inadequate control with high tumor recurrence and neurotoxicity)
Standard initial induction therapy for newly diagnosed primary CNS lymphoma
High dose methotrexate
What might high dose methotrexate cause?
Delated leukoencephalopathy (progressive dementia, gait disturbance) -risk increased when pt gets MTX during or after RT
What therapy might be considered for younger pts with good performance with primary CNS lymphoma?
Intensive chemo followed by autologous stem cell transplantation without whole brain radiation
Most common embryonal brain tumor in children
Medulloblastoma
Where see medulloblastoma in kids?
In or near cerebellar vermis and fourth ventricle (adults are above)
First line tx for medulloblastomsa
Surgery (gross total resection)
Sxs of medulloblastoma
HAs, vomiting (AM), lethargy, gait ataxia
Likely to disseminate and metastasize outside CNS
Presentation of medulloblastoma in cerebellar hemisphere
Ipsilateral ataxia w/ or without signs of increased ICP
Presentation of medulloblastoma in brainstem
Cranial nerve palsies and long tract finding (spasticity, hyperreflexia)
Medulloblastoma on MRI
Homogenously or heterogenously enhancing mass that fills or distorts fourth ventricle
Calcifications or hemorrhage
Hydrocephalus
How to classify medulloblastoma into prognostic groups
Extent of initial surgical resection
Presence/absence of leptomeningeal dissemination at diagnosis
CSF cytology
Tx failure of medulloblastoma
Commonly due to recurrence in posterior fossa with or without leptomeningeal dissemination
Tx for high risk children with medulloblastoma
Multiagent chemo during and after standard radiation improves survival
Where does ependyoma come from?
Ependymal cells which line ventricles and central canal
More common in kids
*fourth ventricle mostly
Common presentation of ependymoma
Hydrocephalus and increased ICP
Most common type of brain tumor
Metastatic tumors
Where do metastatic tumors tend to go to in the brain?
Gray white matter junction in middle cerebral artery terriotry
Order of frequency of metastatic tumors
Lung (lots of non small cell lung cancer pts have them) Breast Melanoma Renal GI tumors
Signs of malignancy
Cachexia Lymphedema Asymmetric breath sounds Breast mass Skin lesions
Clinical manifestations of CNS tumors
Increased ICP: HA (nocturnal or worse in morning, aggravated by coughing, valsalva maneuver or postural change) Nausea Papilledema AMS False localizing signs (CN IV palsy)
Causes of increased ICP with metastatic tumors
Mass effect from tumor
Surrounding edema
Hemorrhage
Hydrocephalus
Very common initial presentation of metastatic tumors
Seizures (partial with secondary generalization-temporal lobe tumors)
Most common presentation of cerebral hemispheric tumors
Seizures
Presentation of tumors in posterior fossa
Ataxia and cranial serve signs
Presentation of tumors in ventricles or near cerebral aqueduct
Signs of increased ICP
Presentation of tumors in spinal cord
Paraparesis, sensory loss, urinary incontinence
Why is CT scan helpful with tumors?
Bone involvement
What is always started with tumors to decrease mass effect and surrounding edema?
Corticosteroid (dexamethasone)
Relative contraindication for tPA
Brain tumors
Tx of VTE with tumors
Low molecular weight heparinoids
