Neoplasms Flashcards
1
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A
2
Q
WHO Grade I lesions characteristics
A
- tumors with low proliferative potential and high possibility of cure following surgical resection alone
- Well demarcated, surgically excisable.
3
Q
WHO Grade I lesion example
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- Example: pilocytic astrocytoma
- occurs @ childhood
- @ cerebellar hemispheres, optic nerves and chiasm, and hypothalamic region.
- Gross total resection possible @ cerebellar lesion
- gross total resection impossible @ optic chiasm or hypothalamus
4
Q
WHO Grade II lesion characteristics
A
- generally infiltrative
- low level proliferative (ie., mitotic) activity,
- often recur.
- Some grade II tumors tend to progress to a higher grade of malignancy
5
Q
WHO Grade II lesion example
A
- Example: diffuse astrocytoma.
- Hits adults age 30-50, has ill-defined borders, not surgically resectable
- Progression examples: low-grade diffuse astrocytomas (WHO grade II) ==> anaplastic astrocytoma (WHO grade III) or glioblastoma (WHO grade IV) over a few years time.
- Similar transformation to higher grade tumor occurs also in oligodendrogliomas and mixed (oligoastrocytomas) gliomas.
6
Q
WHO Grade II treatment
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- watchful waiting (ie., close-interval neuroimaging scans to detect upgrading)
- external beam cranial irradiation, depending on location, clinical features, type and size of lesion.
7
Q
WHO Grade III lesion characteristics & example
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- lesions with histological evidence of malignancy, including nuclear atypia and brisk mitotic activity.
- patients with Grade III tumors receive adjuvant radiation and/or chemotherapy.
- Example: anaplastic astrocytoma: more nuclear atypia
8
Q
WHO Grade IV lesion characteristics
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- cytologically malignant, mitotically active, necrosis-prone neoplasms
- often associated with rapid pre and post operative disease evolution and fatal outcome.
- Common examples of Grade IV neoplasms include glioblastoma and medulloblastoma.
9
Q
Glioblastoma characteristics
A
- WHO Grade IV lesion
- Highly infiltrative, often hemorrhagic neoplasm that is necrotic at the microscopic and sometimes gross level.
- Dismal prognosis. More than 90% of GBMs are primary, only 2-4 months of symptoms.
- Has a bright rim and necrotic center on CT scan.
- Necrotic center releases HIF and VEGF which causes blood vessels to start developing again and vascularizes the rest of the tumor.
- Secondary GBM: progression from lower grade tumor, younger age (
10
Q
General treatment approaches for WHO grade I - IV tumors
A
1: cut it out and it’s ok
2: can’t resect, will often upgrade to grade 3 or 4. Treat with radiation and close observation
3: chemo + radiation
4: rapid growth, fatal, adjuvant therapy has little data supporting use
Tempo parallels grade: Grade 1 grows slowly, grade 4 grows quickly
11
Q
Histologic typing/grading and prognosis
A
- Grading: look at the tumor in microscope and decide how aggressive it will behave (mitotic figures, vascularity and necrosis, invasion).
- Tells you how you will have to treat it and how fast it will kill.
12
Q
Tumor types that tend to spread throughout CSF axis
A
- Astrocytomas and oligodendrogliomas DO NOT ==> into the CSF pathway and disseminate through the cerebrospinal fluid.
- DOES occur late in the course of some ependymomas, especially those in childhood and originating in the 4th ventricle, and especially in medulloblastomas.
