SM_279b: CNS Cancers Flashcards
Most brain tumors are ___
Most brain tumors are secondary (metastatic)
Describe presentation of brain tumors
Brain tumors presentation
- Neuro-anatomical localization determines presenting symptoms and signs
- Generalized symptoms: headache, nausea, vomiting
- Localized symptoms: weakness, sensory symptoms, gait ataxia, visual changes, or language dysfunction
___ is gold standard imaging modality for diagnosing brain tumor
MRI with IV contrast is gold standard imaging modality for diagnosing brain tumor
- Normal contrast enhanced brain MRI excludes a tumor
- Surgical biopsy or excision is necessary for histologic diagnosis b/c imaging characteristics are not definitive
Most common metastases to brain come from ___, ___, and ___
Most common metastases to brain come from lung cancer, breast cancer, and melanoma
___ as sole presenting symptom of brain tumor is rare
Headache as sole presenting symptom of brain tumor is rare
Describe the classical brain tumor headache
Classical brain tumor headache
- Mild at onset, begins when patient awakens in morning and disappears shortly after he or she rises, recurs the following morning
- Gradually increases in frequency, duration, and severity
- Later become constant and associated with other signs of increased ICP such as drowsiness, nausea, and vomiting
- Headache may worsen with changes in ICP such as Valsalva, head shaking, or straightening from a bent position
Describe gliomas
Gliomas
- Arise from neuro-epithelial tissue
- Glial cells account for 90% of cells in the brain
- Morphologically and biologically heterogeneous
- Main histologic subgroups: astrocytoma, oligodendroglioma
- Graded (1-4) but not staged
Describe astrocytic tumors
Astrocytic tumors
- Astrocytes are star-shaped supporting cells of brain and spinal cord: form key component of BBB via foot processes and play active role in creating microenvironment for neurons
- Tumors can be identified by staining for glial fibrillary acidic protein (GFAP)
Describe astrocytoma grading and naming
Astrocytoma grading and naming
- Low grade: grade 1 (pilocytic astrocytoma), grade 2 (diffuse astrocytoma)
- High grade: grade 3 (anaplastic astrocytoma), grade 4 (glioblastoma multiforme)
Describe glioblastoma multiforme
Glioblastoma multiforme
- WHO grade IV
- Thought to arise from astrocytes or their precursors
- Most common malignant primary brain tumor
- Poor prognosis, noncurative
- Median age of onset is 64
- Usually localized to cerebral hemispheres: patients present with symptoms of increased ICP and/or focal neurologic symptoms
- Seizures occur but less frequently than low grade tumors
GBM is managed with ____, ____, ____, and ____
GBM is managed with surgery, medical treatment / chemo, radiation, and tumor-treating fields
Radiation for GBM involves ___
Radiation for GBM involves conventional fractionated external beam radiation therapy with daily temozolomide
Patients with GBM receive post-radiotherapy ___
Patients with GBM receive post-radiotherapy temozolomide chemo for 6 cycles
Fatigue is a side effect
Treatment for GBM involves ____ -> ____ -> ____
Treatment for GBM involves surgery -> temozolomide + RT -> adjuvant temozolomide
- Not curative
Oligodendrogliomas may present with ___
Oligodendrogliomas may present with seizures
- Location and histologic grade correlate with risk
- Low grade, slow growing tumors, and those located in superficial gray matter associated with highest risk
Describe oligodendrogliomas
Oligodendrogliomas
- Usually supratentorial, arising in frontal lobes
- Arise primarily in white matter but tend to infiltrate the cortex more than astrocytomas of a similar grade
- Diffuse infiltration of normal brain prohibit surgical care
- May be heavily calcified
- Histology: fried egg cells
Oligodendroglioma appears as ___ on histology
Oligodendroglioma appears as fried egg cells on histology
Oligodendrogliomas often have ____
Oligodendrogliomas often have 1p19q codeletion
WHO grade II (low grade) and III (anaplastic)
Oligodendrogliomas most commonly present as ____
Oligodendrogliomas most commonly present as focal seizure in young adult
- Median age at diagnosis is 41 years
- May be prolonged period of symptoms (usually focal seizures) prior to diagnosis
Describe treatment / prognosis for oligodendroglioma
Oligodendroglioma treatment / prognosis
- Maximal surgical resection is feasible
- Can see a marked shrinkage of tumor and resolution of symptoms following chemotherapy
- Transformation to anaplastic oligodendroglioma over time: cause of death in most
- Median overall survival is 15 years
Describe meningioma
Meningioma
- Intracranial tumors arising from meningothelial arachnoid cap cells of meningies
- Most are benign (Grade I) slow growing tumors that compress underlying brain but rarely invade it
- Median age at diangosis is 64 years
- Genetic predisposition (NF2) and exposure to ionizing radiation are the only known risk factors
- Focal seizures and neurologic deficits from brain or cranial nerve compression are common
MRI of meningioma shows ____
MRI of meningioma shows diffuse contrast enhancement since meningiomas are outside the BBB
- If patient is asymptomatic or has medically controlled seizures: can be followed without resection
- If treatment indicated, surgery
Vestibular schwannomas are ___ and usually present with ___
Vestibular schwannomas are slow-growing and usually present with gradual unilateral hearing loss, sometimes preceded by tinnitus and vague feeling of dizziness
Bilateral vestibular schwannomas are pathognomonic for ___
Bilateral vestibular schwannomas are pathognomonic for NF-2
- NF-2 is defect on chromosome 22 (merlin protein)
Describe vestibular schwannoma
Vestibular schwannoma
- Surgery can be curative
- Operative morbidity high: hearing loss, facial paralysis
- CN 7 dysfunction seen with large tumors
- Headache often occurs after surgery
Describe CNS lymphoma
CNS lymphoma
- Secondary: metastasis from systemic disease
- Primary: non-Hodgkin’s lymphoma, arises within and is restricted to CNS, immunocompetent patients, immunocompromised patients (EBV)
CNS lymphoma occurs due to ___ and ___
CNS lymphoma occurs due to CNS sanctuary and inflammatory process
- CNS sanctuary: hematopoetic tumor develops outside of CNS, seeds brain, grows b/c CNS is immunologically privileged
- Inflammatory process: lymphocytes traffic into CNS as part of inflammatory process and become transformed into malignant cells
Describe CNS lymphoma clinical features
CNS lymphoma clinical features
- Median age is 66
- Predominantly involves frontal lobes, corpus callosum, deep periventricular brain structures
- Multifocal > 30%
- Cognitive impairment or behavioral change are most common presenting features
- Other symptoms include headache and lateralizing signs
- Symptoms progress over weeks to months
- Classic B symptoms absent
Describe evaluation of CNS lymphoma
CNS lymphoma
- Ocular involvement in 20%: often misdiagnosed as uveitis
- Demonstratable leptomeningeal disease
___ are often used to treat CNS lymphoma
Corticosteroids are often used to treat CNS lymphoma
- Decrease edema
- Exert apoptotic effect on lymphoid cells
- Disease recurs despite continued steroids
Describe treatment of primary CNS lymphoma
Primary CNS lymphoma treatment
- Induction chemotherapy (methotrexate based) followed by consolidation therapy
- Chemosensitive: high dose systemic methotrexate based therapy
- Consolidation therapy: radiosensitive so whole brain RT
Summarize CNS tumors
