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61 Cards in this Set
- Front
- Back
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What does an astrocyte tumor have to be differentiated from?
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A reactive astrocytosis (gliosis)
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What are 2 tumors that originate from astrocytes?
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-Astrocytoma
-Glioblastoma multiforme |
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What is the incidence of astrocyte tumors in all intracranial tumors in all patients?
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21-29%
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What are the 3 classes of Astrocyte tumors?
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-Astrocytoma
-Malignant/Anaplastic astrocytoma -Glioblastoma multiforme |
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What grade are just basic Astrocytomas? What morphology do they exhibit?
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Low grade
-Mod increase in astrocyte # -Slight to mod pleiomorphism -Hyperchromatism |
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What is the prognosis for astrocytoma?
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~5-8 years after diagnosis
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What grade is Malignant/anaplastic astrocytoma?
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2-3
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What morphology is seen in Malignant Astrocytoma?
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-Marked increase in #
-Marked pleiomorphism -Hyperchromatism/Mitoses |
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What is the prognosis for patients with Malignant astrocytosis?
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2-5 years
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What is the grade of Glioblastoma multiforme?
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Grade 3-4
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What 2 histologic features are diagnostic for Glioblastoma multiforme?
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-Vascular proliferation
-Necrosis |
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What 3 other histologic features are often seen in Glioblastoma multiforme?
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-Multinucleated giant cells
-Hemorrhages -Pseudopallisading of tumor cells around necrosis |
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What is the prognosis for Glioblastoma multiforme after diagnosis?
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<1 year even with treatment
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What is a tumor of Oligodendrocytes?
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Oligodendroglioma
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Where do most oligodendrogliomas occur in the brain?
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In the cerebral hemispheres
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What type of progression do Oligodendrogliomas have? What type of symptoms do the produce?
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-Slow growth/progression
-Long standing focal symptoms |
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What is a common symptom of oligodendrogliomas?
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Focal seizures
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What are 2 common gross features of oligodendrogliomas?
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-Highly vascularized
-Calcification |
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What microscopic morphology is seen in oligodendrogliomas?
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The typical FRIED EGG pattern
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What morphology can vascular proliferation in oligodendrogliomas produce?
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Chickenwire patterning of newly formed vessels
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What is a tumor derived from ependymal cells called?
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Ependymoma
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What are 3 locations at which ependymomas can occur, and in what age patients?
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1. Cerebral hemispheres - all
2. Spinal cord - all ages 3. Infratentorial - first decade |
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Where are ependymomas the most common tumor?
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Intramedullary - in the spinal cord
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How do ependymomas tend to behave?
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-Histologically benign
-Clinically malignant |
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Why are ependymomas so clinically malignant?
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Because their location makes total surgical removal difficult.
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What are 2 typical histological features of ependymomas?
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-Perivascular pseudo-rosettes
-Papillary ependymal lining |
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What is the difference between perivascular pseudorosetting and a true rosette of ependymal cells?
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Pseudorosetting is around a vessel
True rosetting is around nothing |
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What are 2 subtypes of ependymomas?
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-Colloid cysts
-Choroid plexus papillomas |
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What is a colloid cyst?
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A congenital cyst lined by Ependyma-like cells in the 3rd ventricle
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What is the proposed origin of the ependyma-like cells of a colloid cyst?
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The intestine
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What is a choroid plexus papilloma derived from?
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Ependymal cells of the choroid plexus
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What type of cells are Medulloblastomas derived from?
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Remnants of the fetal external granular layer (which should only persist until the end of the 1st year of life)
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What type of age distribution do Medulloblastomas exhibit?
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Bimodal
2/3 occur in pts age 5-10 years 1/3 occur in pts age 15-35 |
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Where do medulloblastomas tend to be located in children 5-10?
In adults from 15-35? |
5-10 = in the midline
15-35 = in the cerebellar hemispheres |
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What will the microscopic morphology of a medulloblastoma show?
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-An external granular layer that shouldn't be there
-Small undifferentiated hyperchromatic cells |
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What will the clinical picture of a Medulloblastoma be?
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That of a posterior fossa tumor
-Headaches/signs of incrsd ICP -Ataxia -Nausea -Vomiting |
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Why is it important to know about Medulloblastoma?
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They are the most common infrantentorial, malignant tumor in children
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In what patients are Neuroblastomas most commonly seen?
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Children under 4 yrs old
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What are the 2 most common sites of neuroblastoma?
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-Adrenal gland
-Sympathetic ganglia (behind the peritoneum) |
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How often are neuroblastomas actually primary in the cerebrum?
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Rarely
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What morphology can both Medulloblastomas and Neuroblastomas exhibit?
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Homer-wright pseudorosettes
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What are slowly growing tumors consisting of a mixed neoplastic proliferation of neuronal and astrocytic elements called?
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Gangliogliomas and Ganglioneuromas
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What makes a Ganglioglioma?
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When the predominant cells are glial cells
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What makes a Gangliocytoma?
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When the cells are mostly ganglion cells (more mature)
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What is a Gangliocytoma?
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A tumor of mixed neuron and astrocyte elements, with more mature neurons predominating
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What is a neurocytoma?
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A tumor of mixed neuron and astrocyte elements, with less mature neurons predominating
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What is a tumor consisting of proliferaion of neurons and schwann cells in peripheral nerves called?
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A Ganglioneuroma
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What is a non-neoplastic childhood tumor comprised of neuronal, astrocytic, and oligodendroglial components called?
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Dysembryoplastic Neuroepithelial tumor
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What is a Pineloma derived from?
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Parenchymal cells of the pineal gland
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What is a pinealoma composed of?
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Pineocytes with neuronal differentiation
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What is the malignant form of a pinealoma?
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Pinealoblastoma
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What does a pinealoblastoma look like morphologically?
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Medulloblastoma
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What patients are typically affected with Pinealoma?
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Male children or young adults
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How do Pinealoblastomas frequently behave and what is their prognosis?
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-Spread by CSF seeding
-Poor prognosis |
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How are symptoms usually caused by pinealoblastomas?
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By compression on the -hypothalamus
-midbrain -cerebral aqueduct |
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What are the clinical manifestations of compression by pinealoblastomas?
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-Precocious puberty
-Upward gaze palsy -Cerebellar ataxia -Headache/nausea/vomiting |
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What is a tumor of microglial cells called?
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Primary Lymphoma of the CNS
-Microglioma |
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Why are microgliomas primary lymphoma of the CNS?
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Because they derive from monocytes from the blood circulation
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What is the characteristic feature of lymphoma of the CNS?
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Perivascular infiltration of lymphoid cells
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What is the prognosis for lymphomas of the CNS in general?
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Poor
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Slide 54
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k
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