Gliomas Flashcards
(25 cards)
What are th types of gliomas?
Astrocytomas (WHO Grades I/IV)-most common
Oligodendrogliomas (Grade II)
Ependymomas (Grade II)
Choroid plexus papillomas (Grade I)
Colloid cysts (nonneoplastic lesions)-just lesions
Where can astrocytomas be found?
Cerebral
cerebellar
What is 80% of adult brain tumors?
Astrocytomas
What are the grades for the types of astrocytomas?
Well differentiated (gradeII)
Anapestic astrocytoma (grade III)
Glioblastoma (grade IV)-patients die within a year
What causes Well differentiated defuse astrocytoma (grade II)?
Inactivation of p53, overexpression of PDGF-A
What are the types of Glioblastomas?
2º from a low-grade tumor: younger patients
de novo tumors: older patients
What are the causes of 2º from a low-grade tumor?
P53 mutation, isocitrate dehydrogenase mutation, & PDGFR-A overexpression
What are causes of De nova tumors?
Mutation of PTEN (tumor suppressor) & amplification of EGFR
What are characteristics of a Well differentiated defuse astrocytoma (grade II)?
are poorly defined, gray, infiltrative tumors that expand and distort the invaded brain
–Inactivation of p53, overexpression of PDGF-A
What does low grade (II) astrocytomas histological appearance?
increase in glial cellularity
background of fibrillary appearance
–Inactivation of p53, overexpression of PDGF-A
What are glioblastomas characterized by?
Ring enhancement
very poor prognosis
rapidly growing
What are the characteristics of glioblostomas histologically?
shows high cellularity, numerous mitotic figures, pleomorphism of cells and their nuclei areas of necrosis, proliferation of blood vessels and their endothelium.
What is the most common tumor for children under 10?
Cerebellar (pilocytic) astrocytoma: good prognosis if excised completely
slow growing
Wha type of fibers does a low grade cerebellar polycytic astrocytoma have for histological identification?
Rosenthal fibers
What are the usual locations of Oligodendrogloma?
Cerebral hemispheres
What are the histological characteristics of a oligodendroglioma?
Fried egg morphology -round nucleus with clear cytoplasma
From where does ependymoma arise from?
the ependyma of th eventricles or spinal canal
typacally around the 4th ventricles in children
What are the histological findings of a ependymoma?
Psuedorosette formation around capillaries
Papillary formations with myxoid connective tissue cores are common in tumors of filum terminale
Myxopapillary ependymoma of the spinal cord.
How does choroid plexus pappilloma affects the CSF?
May have hypersecretion or obstruct flow
Where does meningineomas arise from?
outer layer of the arachnoid
Meningioma with te attched dura
What does a primary brain germ cell tumor look alike?
Looks exactly like genital tumors
From where does craniopharyngioma arise?
Arise from Rathke’s pouch
