Lecture 8 and 12 -- CNS Tumors + Path Flashcards
what is the most common malignancy to the brain?
Metastatic disease – 50% from the Lung
where do most ped tumors occur? where do most adult tumors occur?
Peds – 75% in Posterior Fossa
Adults – 75% in cerebral hemispheres
WHO grading system (using astrocytoma as an example; describe the progression and associated micropath at each grade)
Grade 1 – ?
Grade 2 – Diffuse Astrocytoma – some atypical cells but no mitotic activity
Grade 3 - Anaplastic Astrocytoma – Increased cellularity and mitotic activity
Grade 4 - Glioblastoma – vascular proliferation/endothelial patches, necrosis, pseudopalisading
What is meant by the term “diffuse”?
infiltrate the brain as individual cells; wonder out into the brain parenchyma
therefore technically non curable and start as grade 2 tumors
Glioblastoma –
pathognomonic micropathology finding?
Psuedopalisading
Primary vs secondary glioblastomas?
Primary – Preseents as glioblastoma, not an evolving precursor lesion.
Secondary – Evolves from Precursors
Glioblastoma –
Median survival and pathogenesis?
Treatment ?
marker to test for?
the most common Primary CNS Malignancy
<12 month median survival. Characteristic rapid progression, significant mass effect, edema
Treatment: Cannot resect
Tx = Radx + Temozolomide
MGMT methylation
What is the significance of an MGMT mutation for Glioblastoma treatment?
MGMT negates the effect of Temozolomide
therefore if there is an MGMT methylation, the gene is silenced and patient responds better to Temozolomide therapy
Unmethylated MGMT = negative prognostic factor (irrespective of treatment)
Anaplastic oligodendroglioma –
Pathognomonic pathology?
genetic mutation/marker ?
prognostic significance?
Friend Egg with Chicken wire
1p/19q Co Deletion – positive prognostic factor
name 3 low grade gliomas ?
what is the standard therapy?
what is the median survival time?
§ Diffuse astrocytoms – 5 years
Oligoastrocytoma – 7.5 years
Oligodendroglioma – 10 years
13.3 year Median Survival – with RT + PCV
Ependymoma –
who ?
Gross path ?
buzzword for histo path?
more common peds tumors
Gross Path - well demarcated lesions
Histopath –
Pseudorossettes – lack true lumen
Rossettes – True Lumen
• Myxopapillary Ependymoma –
where does it occur?
presenting symptom?
benign vs malignant?
benign lesion of the filum terminale
Sx – back pain
pituitary Adenomas –
How common?
where do they occur?
presenting symptoms related to this location?
what percentage are secretory?
10-15% of all CNS neoplasms
Arise in Sela Tursica
Can lead to diplopia/bitemporal hemianopia
70% are secretory
Treatment for prolactinoma?
Treatment for GH secreting tumor?
Prolactima – Dopamine Agonists (Bromocriptin, Cabergoline)
GH secreting tumors – Octreotide (somatostatin analog)
+ radiotherapy
Meningioma
- how common is it?
- from what cells do they originate? where do they arppear?
The most common benign CNS Primary (90% are benign)
- Arise from arachnoid cap cells
- commonly at the dural base and well circumscribed
Meningioma –
molecular pathology?
Histopathology?
– Loss of 22q12.2 tumor suppressor (including Merlin/Schwannoma)
– Histo: “Whorls” and Psammoma bodies
Meningioma Treatment?
what is the best predictor of failure/recurrence?
GTR
STR + External Beam Radiation
• Extent of the resection is predictor of failure
name 4 childhood primary tumors
Pilocytic Astrocytoma (benign, good prognosis)
medulloblastoma (Malignant)
Ependyoma (poor prognosis)
Craniopharyngioma (Benign)
Pilocytic Astrocytoma –
where does it commonly occur?
Gross path?
Histopath?
Posterior Fossae (Cerebellum)
Gross Path; Cystic appearance with “mural nodule”
Histo Path? Biphasic Architecture + rosenthal Fibers
medulloblastoma classified as a ...? where does it occur? Gross Path? Histopath?
Tendency for what other manifestation?
pathogenesis/progression?
Treatment?
Primitive Neuroendocrine Tumors (PNET), but occurs in the cerebellum and therefore Medulloblastoma
Gross Path – Poorly circumscribed with necrotic hemorrhage
Histopath – Homer Write Pseudorossettes
Tendency for CSF obsturction leading to hydrocephalus
Progression: disease is very aggressive and spreads through the CSF
Treatment: Surgical treatment followed by Craniospinal Radiation and Chemotherapy
Craniopharyngioma
- who gets these tumors?
- benign vs malignant?
- Arises from what embryological structure?
Treatment ?
Benign tumor of children, but there is bimodal distribution and adults can get them too
Arise from remnants of Rathke’s Pouch
Treatment: GTR > STR + RT
Hemangioblastoma –
associated with what familial disease?
imaging findings?
where does it commonly present?
produces what hormone?
Histology?
A/w Von Hippel Lindau
imaging: Cystic Mural nodule in the cerebellum
Can produce EPO and lead to secondary polycythemia
Histo: Thin walled capillaries with minimal intervening parenchyma
what is the classic peripheral nerve sheath tumor?
8th cranial nerve schwannaoma
8th cranial nerve schwannoma
aka
- where is the lesion seen on imaging?
Histopath findings?
commonly seen in what tumor syndrome?
aka Vestibular schwannoma
Imaging: Cerebellopontine angle;
Histo:
Antoni A – pink with “Verocay bodies” — (the nuclear free zones)
Antoni B – pale
Commonly seen with NF2
