Path: Neuro Tumors Flashcards
Most common presenting signs and symptoms of Infiltrating Astrocytomas?
Seizures, headaches, and focal neurologic deficits related to the site of involvement
What are the 2 seperate subtype of Ependymomas and which is more serious?
- Mesenchymal subtype = younger patients, more likely to develop metastases w/ a worse prognosis
- Second w/ aberrations of large regions of chromosomes, but have better prognosis
What is an important consideration in regards to limbic encephalitis and malignancy?
The syndrome appears before any malignancy is suspected
Gangliogliomas are most commonly found in the _______ lobe and have a _____ component
Gangliogliomas are most commonly found in the temporal lobe and have a cystic component
What is the function of the proteins hamartin and tuberin produced by the tuberous sclerosis genes?
How does dysregulation of these proteins lead to the histological characterstics of tumors associated w/ tuberous sclerosis?
- Inhibit the kinase mTOR
- mTOR is key regulator of protein synthesis and other aspects of anabolic metabolism, including control of cell size
*Tumors associated w/ tuberous sclerosis are remarkable for having voluminous amounts of cytoplasm!
What are the most common mutations seen in Oligodendrogliomas; which have a better prognosis?
- IDH1 and IDH2 (better prognosis)
- 1p19q (favorable prognosis)
- CDKN2A
What are the 2 tuberous sclerosis locuses; associated chromosome; and protein each encodes
Which is more commonly mutated?
- TSC1 on chromosome 9q34 encodes hamartin
- TSC2 on chromosome 16p13.3 encodes tuberin = Most commonly mutated
What is a risk factor for the development of Meningiomas?
Prior radiation therapy to the head and neck, typically decades earlier
Tumor where the predominant neoplastic astrocyte has a brightly eosinophilic cell body from which emanante abundant, stout processes describes what?
Gemistocytic astrocytoma
What is the histologic pattern characteristically produced by Glioblastomas?
Pseudo-palisading: tumor cells collecting along the edges of necrotic regions
Cowden syndrome is associated with what tumor; due to what mutation?
- Dysplastic gangliogliocytoma of the cerebellum (Lhermitte-Duclos disease)
- Mutations in PTEN resulting in PI3K/AKT signaling pathway activity
NF1 is more common and is characterized by which malignancies and other findings?
- Neurofibromas of peripheral nerve
- Gliomas of optic nerve
- Pigmented nodules of the iris (L**isch nodules)
- Cutaneous hyperpigmented macules (cafe au lait spots)
What is the treatment for some of the paraneoplastic syndromes and in general which are the best responders?
- Immunotherapy (removal of circulating antibodies and immunosuppression)
- Those with plasma membrane-reactive antibodies (i.e., VGKC and NMDAR) respond better
What is a frequent clinical manifestation of posterior fossa ependymomas?
Hydrocephalus (non-communicating) secondary to progressive obstruction of the 4th ventricle
Which type of infiltrating astrocytoma belongs to the Grade II-IV designation?
Grade II: diffuse astrocytoma
Grade III: anaplastic astrocytoma
Grade IV: glioblastoma (this is malignant)
Atypical Teratoid/Rhabdoid Tumors are most commonly seen in whom and where are they seen in the brain?
Benign or malignant?
- Highly malignant tumor (grade IV) of young children (most often before age 5)
- Posterior fossa and supratentorial compartments
What grade of tumor is a Pilocytic Astrocytoma?
- I/IV
- Benign
Which receptors may be expressed by Meningiomas and which patient population can this potentially affect?
- Progesterone and Estrogen receptors
- Pregnancy increases symptomatic presentation NOT incidence
Which markers of CNS germ cell tumors may be helpful in assisting with diagnosis and tracking response to therapy?
- α-fetoprotein
- β- hCG
Where in the brain are Oligodendrogliomas most often seen?
Cerebral hemispheres w/ predilection for white matter
Pilocytic Astrocytomas generally occur during what decades of life?
Where in brain do they typically occur?
- First 2 decades of life
- Cerebellum and floor/walls of 3rd ventricle, occasionally cerebral hemispheres
Metastasis of which type of germ cell tumor to the CNS is common?
What is the significance of this in regards to classifying the tumor?
Gonadal germ cell tumors
*Why the presence of a non-CNS primary tumor must be excluded before a diagnosis of primary germ cell tumor of the CNS is made!
Among the higher grade astrocytomas, presence of what mutation is associated with a better outcome?
Mutant form of IDH1
Medulloblastomas are often located where?
Midline of the Cerebellum
When are Oligodendrogliomas most commonly seen (decades)?
How are they graded?
- Most common in fourth and fifth decades
- Grade II/IV
What is an important clinical symptom of Colloid Cysts of the 3rd Ventricle?
Headache, sometimes positional (worse when standing up)
Meningeal carcinomatosis with tumor nodules studding the surface of the brain, spinal cord, and intradural nerve roots is most commonly associated with carcinoma of the _______ and _______.
Lung and Breast
Which rare tumor has a high likelihood of metastasing to the brain?
Choriocarcinomas
What is the most common mutation seen in Meningiomas without NF2 mutations?
What is the histologic grade of this type?
- TNF-receptor associated 7 (TRAF7)
- Lower histologic grade
What is responsible for the polycythemia observed in hemangioblastomas associated with Von Hippel-Lindau Disease?
VHL is involved in regulating expression of erythropoietin —> Polycythemia
What is the typical patient presentation for a Meningioma?
Present with vague non-localizing signs and symptoms or with focal findings due to compression of underlying brain
What are the common histologic findings of metastases to the CNS?
Nodules of tumor, often with central areas of necrosis, surrounded by reactive gliosis
Medulloblastomas that occur in older children tend to have what genetic mutations?
- Mutations in WNT signaling pathway
- Monosomy of chromosome 6
- Nuclear expression of β-catenin
What are the 5 most common primary sites for potential metastasis to the brain?
- Lung
- Breast
- Skin (melanoma)
- Kidney
- GI
What is the prognosis of Intrinsic Pontine Gliomas?
Aggressive and short survival (most common brainstem gliomas)
What is the grade for most Ependymomas?
Grade II/IV
Tuberous Sclerosis Complex is characterized by the development of what?
Most frequent clinical manifestations are?
- Development of hamartomas and benign neoplasms involving the brain and other tissues
- Seizures, autism, and mental retardation
When Ependymomas occurs in adults they are most often associated with what other condition; due to what mutation?
NF2 – due to mutation on chromosome 22
Which tumor of the CNS is characterized by whorled clusters of monotonous cells; psammoma bodies?
Meningioma
Group 3 medulloblastomas (worst prognosis) tend to occur in infants-young children and are associated with what mutations?
- MYC amplification
- Isochromosome 17 (i17q)
Which features distinguish an Anaplastic Oligodendroglioma (III/IV) from an Oligodendroglioma?
Vascular hypertrophy, necrosis, and nuclear anaplasia
What is a common complication due to Medulloblastomas propensity to form linear chains and infiltrate?
- May infiltrate cerebral cortex and penetrate the pia, spreading into subarachnoid space
- Dissemination through CSF is common complication, giving rise to nodular masses some distance from the priamry tumor (i.e., as far as the cauda equina) – Drop Metastases
Contrast ring enhancing lesions, with hypodense central necrosis is characteristic of what kind of tumor?
Glioblastoma
Which grade of tumor is considered infiltrative?
Grade II
What is the mnemonic using VHL for Von Hippel-Lindau Disease?
- V = VHL gene
- H = Hemangioblastoma
- L = Lots of catecholamines = pheochromocytoma
*VHL = 3 letters = RCC (renal cell carcinoma)
*VHL = 3 letters = chromosome 3
Alterations in what signaling pathway have been found in Pilocytic Astrocytomas?
BRAF signaling pathway