L12- CNS Tumors Flashcards
list the common places CNS tumors arise
- Meninges (*menigiomas)
- Brain (*gliomas, neuronal tumors, choroid plexus tumor)
- Others: CNS lymphoma, germ cell tumors
- Metastasis
Brain Tumors:
- (1) local effects, generally
- (2) diffuse effects, generally
1- seizure, compression of nerve or vessel (=> necrosis)
2- inc ICP => confusion, ataxia, n/v, incontinence, HA
categorize the CNS tumor types
Primary
- Intrinsic: *Gliomas (astrocytoma, oligodendroglioma, ependymomas), Neuronal tumors, *Embryonal neoplasm / medulloblastoma
- Extrinsic: *Meningiomas, *Schwannomas, Pituitary adenoma
Secondary
- metastasis
- lymphoma (especially in immunocompromised Pts)
Primary CNS tumors:
- Children: (1) relative location, (2) most common types
- Adults: (3) relative location, (4) most common types
Children- 20% of all tumors are brain tumors
1- infratentorial (posterior fossa, includes cerebellum)
2- astrocytoma, medulloblastomas, glioblastomas, ependymomas
3- supratentorial
4- astrocytoma, glioblastomas, oligodendroglomas, mestastatic tumors, meningiomas
list the types of gliomas
astrocytoma, oligodendroglioma, ependymoma
diffuse astrocytoma:
- (1)% of all gliomas
- (2) age of onset
- (3) location of tumor
- (4) tumor marker
(glioma) 1- 80% 2- 30s-50s 3- both cerebral hemispheres (diffuse locations -- not one solid mass) 4- GFAP- glial fibrillary acidic protein
GFAP is the tumor marker for….
(glial fibrillary acidic protein) diffuse astrocytoma (glioma)
briefly describe the grades for diffuse astrocytomas
(glioma // based on Histology) I- manageble Tx II (diffuse astrocytoma)- can remain stable for years III (anaplastic astrocytoma) IV (glioblastoma)- rapid deterioration
describe the main gross pathological features for diffuse astrocytoma
(glioma // grade II, III)
- poorly defined gray infiltrating tumor distorting brain contours
- doesn’t form a discrete mass
describe features of diffuse astrocytoma on MRI
(glioma)
ring enhancing mass in many locations
Glioblastoma, gross pathological features
(highly variable)
- firm + white — soft + yellow due to necrosis (rapid growth exceeds angiogenesis speed)
- cystic degeneration, hemorrhage- via rapid growth > angiogenesis
-butterfly shaped appearance- since it crosses midline
Glioblastoma, microscopic pathological features
eosinophilic necrotic foci:
- pseudo-palisading (enclosure) of malignant nuclei
- endothelial cell proliferation
pilocytic astrocytoma:
- (benign/malignant)
- (2) affected age group
- (3) common tumor location
(glioma)
1- benign
2- children, young adults
3- cerebellum – may also involve 3rd ventricle, optic paths, spinal cord, hemispheres
pilocytic astrocytoma:
- related to (1) genetic changes
- (2) is an associated development with the tumor
(glioma)
1- BRAF translocations
2- cysts –> they can enlarge to cause many other symptoms
Oligodendroglioma:
- (1) affected age group
- (2) describe progression
- (3) common tumor location
1- 30s-40s
2- insidious growth –> several yrs for Sxs to develop
3- cerebral hemispheres- mostly frontal* and temporal (*highly myelinated areas)
Ependymoma:
- (1) predominant locations
- (2) most common location for <20y/o
- (3) most common location for adults, which is associated with (4) genetically
(glioma) 1- ependyma lined ventricular cavity + central canal of spinal cord 2- 4th ventricle 3- spinal cord 4- NF-2
Ependymoma, microscopy:
- (1) cell features
- (2) surrounding features
- (3) cell-to-cell features
- (4) surrounding cell-to-cell features
(glioma)
1- cells appear normal, round/oval nuclei, abundant granular chromatin
2- variable, fibrillary
3- rosette formation –> long delicate processes extending into lumen
4- pseudo-rosettes are perivascular
Embroyonal tumors:
- (1) origin
- (2) main cellular feature
- (3) most common tumor
1- neuroectodermal origin
2- small round cells
3- medulloblastoma
Medulloblastoma:
- affects (adults/children)
- (2) common location
- (3) related genetic defects
(embryonal tumor)
1- children
2- cerebellum
3- Wnt-β catenin pathway, MYC overexpression
Medulloblastoma:
- (1) malignancy and prognosis
- (2) are common and useful clinically in most tumors
- (3) is an important feature related to treatment
(embryonal tumor)
1- highly malignant, poor prognosis
2- neuronal and glial tumor markers
3- very radiosensitive
Medulloblastoma, gross appearance
(embryonal tumor)
- well-circumscribed
- gray
- friable
- may involve leptomeninges (arachnoid + pia, CSF inbetween)
Medulloblastoma, microscopic features
(embryonal tumor)
- sheets of small, round, blue anaplastic cells
- hyperchromatic nuclei + abundant mitosis — scant cytoplasm
- rosettes
Meningioma:
- (1) cell origin
- (benign/malignant)
- affects (adults/children)
- (4) tumor location
1- arachnoid meningothelial cells (attached to dura mater)
2- benign
3- adults
4- external surface of ventricular system (attache to dura mater)
Meningioma:
- (1) basis of prognosis
- (2) clinical features
- (3) clinical associations (+ genetic)
1- depends on size, location, surgical accessibility, histological grade
2- vague non-localizing Sxs + focal Sxs with compression of adjacent brain
3:
-multiple meningiomas + 8th nerve schwannoma OR glial tumor (NF-2)
Menigioma:
- (1) gross features
- (2) microscopic features
1- well defined mass –> compression w/o invasion
2:
- whorled, tight clusters of cells w/o visible cell membrane
- some with psammoma bodies (calcified necrotic tissue)
Schwannoma:
- (benign/malignant) tumor arising from (2)
- (3) is alternate name (hint- its a misnomer)
- (4) symptoms
1- benign
2- peripheral nerves
3- acoustic neuroma
4- local compression of CN-8 => tinnitus, hearing loss
Schwannomas are commonly associated with a (loss/gain)-of function mutation of (2) gene for (3) protein on chromosome (4).
1- loss-of-function
2- NF-2
3- merlin
4- chr.22
Schwannomas:
- (1) gross features
- (2) and (3) are the separate microscopic areas (include features for both)
- (4) features between main structures in (2)
1- firm, gray masses
2- Antoni A: dense, eosinophilic, spindle cells with cellular intersecting fascicles, palisading (enclosed) nuclei
3- Antoni B: loose
4- nuclear free zones- Verocay bodies
tumor- positive test for IDH-1/2 mutation indicates….
better prognosis in glioblastoma
tumor- positive test for 1p and or 19q deletions indicates….
better prognosis in oligodendroglial tumors
tumor- positive test for β-catenin expression indicates….
better prognosis for medulloblastoma
Metastatic tumors:
- (1)% of all intracranial tumors
- most originate from (2) type tumors, commonly from (3) locations
- (4) is the main location of metastasis
1- 25-50%
2- carcinomas
3- lung, breast, melanoma, kidney, GIT
4- gray-white matter junction —> sharply demarcated mass
