CNS Neoplasms - Ojemann/DeMasters Flashcards
Pilocytic Astrocytoma (Epidemiology/age, location, WHO grade, genetics, histology, staining)
Age - Common in children (the most common CNS neoplasm of childhood)
Location - Cerebellum, optic pathway, hypothalamus [thalamus, spinal cord, temporal lobe]
WHO classification - WHO Grade I, easy surgical resection for CURE
Genetic mutation - BRAF/KIAA mutation leads to Oncogene Induced Senescence
Histology/Other - Rosenthal fibers, immunostain GFAP.
Other - Assx with NF1 (neurofibrin involved in the RAS/RAF pathway)
Ganglioglioma (WHO Grade, histologic features/location)
Not mentioned in lecture.
WHO grade I
Calcified, well circumscribed, often in the temporal lobe.
Choroid Plexus Papilloma (WHO Grade)
WHO Grade I
NOT an ependymoma. Causes obstructive hydrocephalus by blocking the foramina
Diffuse Astrocytoma
Age - 30/40
Location - Cerebral hemispheres (occurs where pilocytic astrocytoma doesn’t)
WHO Grade II - not amenable to surgical resection
Oligodendroglioma (Age, location, WHO grade, Genetics, Histology)
Age: 42 (mean)
Location: Cerebral white matter (frontal/parietal/temporal/occipital, 3:2:2:1 by mass)
WHO Grade II
Genetics: 60-80% have LOH 1p, 19q, positive survival factor
Histology - Bright white calcifications on imaging, “fried egg” appearance on histology.
MNEMONIC: Oligodendrogliom”egg”: Ca in the fried-eggshell.
Ependymoma (Age range, location (pediatric/adult), WHO grade)
Age: Pediatric (0-20)
Location: intraventricular (4th ventricle), often present with obstructive hydrocephalus. Spinal cord = adult
WHO Grade II or III
Anaplastic Astrocytoma (Age, location, WHO grade, genetics, histology)
Age - 45 years (mean)
Location - Cerebral Hemispheres
WHO Grade III - Nonresectable
Genetics - TP53 mutation (grandparent is IDH, along with oligodendroglia)
Histology - more mitoses but no vascularization/necrosis (mitotic increase, not size gives the WHO III score) more atypical nuclei
Anaplastic Oligodendroglioma (Age, location, WHO grade, Genetics, histology)
Age: 42 years (mean)
Location: Cerebrum (3/2/2/1)
Who Grade III: grading is more lenient for the oligodendrogliomas than for the astrocytomas, so some vascularization and necrosis is allowed, while still remaning a WHOIII. An asytrocytoma with these characteristics would be a GBM)
Genetics: 60-80% have 1p, 19q, positive predictor of survival (detect with FISH, look for deletion - red dot missing)
Histology: MIB1 immunostain highlights cells not in G0, allows distinction of cells not visible on LM.
Glioblastoma (GBM) (Age, location, WHO grade, genetics, histopathology, other)
Age: Primary (62) Secondary (45)
Location: Cerebral hemispheres
WHO Grade IV
Genetics: “Paracrine growth loop”–> Hif1–>VEGF–>vascularization
Histopathology: highly necrotic/mitotic/dedifferentiated. Cause “leaks” in the BBB, leading to bright signals on MRI
Other: sometimes arise in multiple sites at once (can pretend as metastatic). less than 3% 5 year survival.
**The term glioblastoma is synonymous with astrocytoma, WHO grade IV.
Medulloblastoma (Age, epidem, location, mortality, WHO grade, other)
Age: Pediatric (3-8 y/o). THE most common malignant tumor in children.
Location: Cerebellum, by definition
ALL MEDULLOBLASTOMA ARE GRADE IV!!!!!!!!!!!!!!!
50% survival
Other: MEDULOBLASTOMA are an exception to the rule that brain tumors don’t metastisize. They tend to spread through the CSF pathways. This is opposed to all other tuors of the brain which almost never spread.
Meningiomas (Age, location, WHO grade, other)
Age: women in their 50s (due to presence of estrogen receptor - Pathoma). Almost never in children.
Location: Dura/calvarium
WHO Grade I (stated twice in lecture)
Other: “push and shove, don’t invade” Typical appearance – superficial, often attx to dura. Bulbous mass with pseudopod extensions (dural tail). Makes for an easy neuroimaging diagnosis. Can also extend through bone. Can occur in a variety of locations. These tumors are not fatal today…but only as a result of very complex and difficulty surgeries if in difficult locations.
Schwannomas (Speed, location, other names)
Slow growing, rare transformation to malignancy
Tumors of nerve and nerve covering. Olfactory bulb and optic nerve use CNS (oligo). The rest of the cranial nerves use schwann cells. Cranial nerve 8 is the most common, hence acoustic neuroma. Commonly presents with tinnitus.
[Bilateral acoustic neuroma assx with NF2 - Pathoma]
Most brain tumors are primary/metastatic?
Metastatic (150,000) vs (35,000 primary)
What three types of tumors are “gliomas”? From what tissue (precursor) do they arise?
Astrocytomas
Ependymomas
Oligodendrogliomas
Arise from the neuroectoderm.
What are the 5 most common sites for metastases to brain?
Breast Lung Kidney GI Melanoma
