Chapter 28: Tumors Flashcards
(126 cards)
Which grade of tumor is considered infiltrative? aka what stage does a tumor become infiltrative?
Grade II
In which decade of life are Grade II, III, and IV Astrocytomas found?
- Grade II: usually 3rd-4th decase
- Grade III: usually 5th decade
- Grade IV: usually 6th decade and beyond
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, optic nerves, spinal cord, and occasionally cerebral hemispheres
What grade of tumor is a Pilocytic Astrocytoma?
- I/IV
- Benign
What are the distinguishing morphological characteristics of Pilocytic Astrocytomas?
- Well-circumscribed, often CYSTIC w/ a mural nodule
- Biphasic pattern (alternating loose and compact regions of tumor growth)
- Hair-like cells w/ long bipolar processes
- Rosenthal fibers
- Eosinophilic granular bodies (EGBs) (mark of slow growing tumors)

Which disease predisposes patients to Pilocytic Astrocytomas and due to what?
NF-1 due to functional loss of neurofibromin
Alterations in what signaling pathway have been found in Pilocytic Astrocytomas?
BRAF signaling pathway
Which brain tumor appears as a cystic mass with a mural nodule?
Pilocystic astrocytoma

Which 3 tumors are part of the Glioma family?
- Astrocytoma
- Oligodendroglioma
- Ependymomas
Most common presenting signs and symptoms of Infiltrating Astrocytomas?
Seizures, headaches, and focal neurologic deficits related to the site of involvement
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)
what is the mutant protein that causes 90% of cases of infiltrating astrocytomas?
IDH1 R132H mutant protein IHC
Among the higher grade astrocytomas (grades II-IV), presence of what mutation is associated with a better outcome?
Mutant form of IDH1
what is the gross appearance of an infiltrative astrocytoma?
there is blurring of the corticomedullary junction
Tumor where the predominant neoplastic astrocyte has a brightly eosinophilic cell body from which emanante abundant, stout processes describes what?
Gemistocytic astrocytoma
What are the 3 histology hallmarks of glioblastoma?
Pseudo-palisading: tumor cells collecting along the edges of necrotic regions
Necrosis: serpentine
Vascular/endothelial proliferation

Necrosis in glioblastoma often occurs in a ________ pattern in areas of hypercellularity
Serpentine
Which additional features differentiate a glioblastoma from anaplastic astrocytomas?
Necrosis and vascular (glomeruloid type)/endothelial cell proliferation
What characteristic of Glioblastomas is seen on MRI?
Contrast ring-enhancing, hypodense central necrosis
Which tumor often crosses the corpus callosum and produces a “butterfly” appearance
Glioblastoma

Contrast ring enhancing lesions, with hypodense central necrosis is characteristic of what kind of tumor?
Glioblastoma
Which tumor is most often found in the temporal lobe in children and young adults, usually with a history of seizures?
Pleomorphic Xanthoastrocytoma
What distinguishes a Pleomorphic Xanthoastrocytoma from more malignant types?
What is the grade and prognosis of this tumor?
- Abundant reticulin deposits, absence of necrosis and mitotic activity
- Grade II/IV w/ 5-year survival rate of 80%
What is the most common Brainstem Glioma?
Intrinsic pontine glioma



