TUMORS Flashcards
astrocytomas are probably derived from __________) that have been stimulated by
different oncogenes.
Neural stem cells (NSCs
Only two astrocytoma subtypes—_______—are considered truly benign
pilocytic and
subependymal giant cell astrocytomas
All diffusely infiltrating
astrocytomas are at least WHO grade_____ neoplasms
II
A rare variant of pilocytic astrocytoma called __________ can also present in infants, generally as a
large H-shaped hypothalamic mass that extends laterally into one or both temporal lobes
pilomyxoid astrocytoma
SEGAs are almost exclusively found in the
________, attached to the septi pellucidi.
lateral ventricle near the foramen of Monro
Cerebellar and tectal plate astrocytomas are usually _________, whereas most brainstem “gliomas” are diffusely infiltrating ________
pilocytic astrocytomas
fibrillary astrocytomas
__________________ is the most common of all primary CNS neoplasms in patients between the ages of 18 and 30 years. Most occur in the hemispheric white matter
Diffusely infiltrating astrocytoma (WHO grade II)
MC adult astrocytoma
Diffusely infiltrating astrocytomas are the most common tumor type
Pilocytic astrocytoma, sometimes termed “juvenile pilocytic astrocytoma” or “cystic cerebellar astrocytoma,” is a well-circumscribed, typically ______
slow-growing glioma of young patients.
The second most common site of pilocytic astrocytoma is _______________, which
together account for between one-quarter and one-third of all PAs
around the optic nerve/chiasm and hypothalamus/third ventricle
The classic finding of PA is a biphasic pattern of two distinct astrocyte populations.
The dominant type is composed of compact, hair-like (“pilocytic”) bipolar cells with _________(electron-dense
glial fibrillary acidic protein [GFAP]-positive cytoplasmic inclusions) (17-5).
Intermixed are loosely textured, hypocellular, GFAP-negative areas that contain _______
Rosenthal fibers
multipolar cells with microcysts
The most common appearance of a
posterior fossa PA is a ______
well-delineated cerebellar cyst with a mural nodule.
MRS in PAs often shows _________________—paradoxical findings that are more
characteristic of malignant neoplasms than this clinically benign-behaving tumor
elevated Cho, low NAA, and a lactate peak
In PMA, Rosenthal fibers and the characteristic biphasic pattern of PA are absent, Instead, PMAs
consist of ________
monomorphic piloid tumor cells embedded in a striking, mucopolysaccharide-rich myxoid matrix
T or F, Patients with PMAs generally have a better prognosis that those with PA
F
worse