Nervous System Malignancies Flashcards

Question

classifications of astrocytomas

Answer 1

*non-infiltrative/localized: pilocytic astrocytoma (grade I) *infiltrative: -diffuse astrocytoma (grade II) -anaplastic astrocytoma (grade III) -glioblastoma (grade IV)

Answer 2

*BENIGN neoplasm of astrocytes (grade I); non-infiltrative -most common benign CNS tumor in children -very slow growing, usually arises in cerebellum

Answer 3

*mutations/translocations involving BRAF (functions in RAS signaling pathway) *IDH1 mutations NOT seen

Answer 4

*discrete CYSTIC lesion with mural nodules *biphasic architecture: loose "microcystic" and compact, densely fibrillar areas *ROSENTHAL FIBERS: bright-red corkscrew-shaped astrocyte inclusion

Answer 5

*MALIGNANT neoplasms of astrocytes (grade II-IV) *account for 80% of adult gliomas, usually in the 40s-60s *low-grade tumors progress to high-grade tumors *on imaging, low grade is non-enhancing, and high-grade is enhancing

Answer 6

*grade II (infiltrative) astrocytoma *most common in young adults *IDH1 mutations *transition between neoplastic and normal tissues not distinct: -infiltrate diffusely -increased cellular astrocyte proliferation with atypia -mitoses RARE -microvascular proliferation + necrosis ABSENT

Answer 7

*grade III (infiltrative) astrocytoma *IDH1 mutations *transition between neoplastic and normal tissues not distinct: -mitoses increased -microvascular proliferation -necrosis ABSENT

Answer 8

*grade IV (infiltrative) astrocytoma *most common and most malignant primary brain tumor or adults (commonly crosses corpus callosum - "butterfly" lesion) *NOT associated with IDH1, unless progression from lower grade *transition between neoplastic and normal tissues not distinct: -highly pleomorphic -mitoses numerous -extensive endothelial proliferation and areas of necrosis

Answer 9

*malignant neoplasm of oligodendrocytes *constitute 5-15% of gliomas *best prognosis among glial tumors (survival of 10-20 years, depending on grading)

Answer 10

*IDH1/2 mutation AND *deletion of 1p and 19q

Answer 11

patients may have had several years of neurologic complaints, often including seizures

Answer 12

*usually frontal lobe *predilection for white matter *gelatinous, gray masses, often cystic, focal hemorrhages, and calcifications

Answer 13

*regular cells with spherical nuclei *clear halo cytoplasm, "fried eggs" *grade II = low mitotic activity *grade III = anaplastic, higher cell density, anaplasia, increased mitoses, necrosis

Answer 14

*malignant neoplasm of ependymal cells *10% of pediatric brain tumors (typically posterior fossa) *in adults, typically spinal cord (22q deletion ; NF2 gene mutation)

Answer 15

*posterior fossa -> non communicating hydrocephalus (progressive obstruction of 4th ventricle) *CSF dissemination uncommon

Answer 16

*cells with fibrillary processes contain regular nuclei *canals = glandlike elongated structures with lumen (resembling embryologic ependymal canal) *pseudorosettes = perivascular nuclear-free zones

Answer 17

*malignant neoplasm of cerebellar stem cells *accounts for almost 20% of pediatric tumors *most tumors located cerebellum midline *molecular groups vary in terms of age of onset, tumor location, and prognosis

Answer 18

*posterior fossa -> non communicating hydrocephalus (progressive obstruction of 4th ventricle) *CSF dissemination: meningeal "icing" or spinal "drop mets" *highly malignant; however, exquisitely radiosensitive

Answer 19

*densely cellular, undifferentiated small blue cells (embryonal) *Homer-Wright rosettes surrounding central neuropil

Answer 20

*predominantly benign neoplasms of arachnoid meningothelial cells *found along any of the external surfaces of the brain (usually attached to dura) *most common benign CNS tumor in adults (rare in children)

Answer 21

*loss of long arm chromosome 22 (22q deletion) -including NF2 gene, which encodes the protein merlin -about 50% of sporadic meningiomas have loss-of-function mutations of NF2 *increased risk with prior radiation therapy to head/neck

Answer 22

*slow-growing, solitary tumors *vague non-localizing, or focal referable symptoms to adjacent brain compression *may express variety of hormones (grow rapidly during pregnancy)

Answer 23

*round mass attached to dura (may compress underlying brain) *common sites: -parasagittal convexity -lateral convexity -sphenoid wing, olfactory groove, sella turcica

Answer 24

*push, rather than infiltrate *compact clusters/whorls of cells *psammomatous calcifications *malignant variants = high grade)

Answer 25

*metastatic meningeal or parenchymal brain lesions *account for 25-50% of intracranial tumors

Answer 26

*may be first manifestation of systemic disease *present as mass lesions: may be multiple; meningeal carcinomatosis *common primary sites = LUNG, breast, skin, kidney, GI

Answer 27

*intraparenchymal sharply demarcated masses (usually at gray-white matter junction) *typically resemble parent tumor type (phenotyping helpful for identifying the primary neoplastic site)

Answer 28

*benign neoplasm of Schwann cells *nerve sheath tumors *arise directly from peripheral or cranial nerves (may arise within dura) *inactivating mutations of NF2 gene on chromosome 22

Answer 29

*local compression of involved nerve or adjacent structures *dural: acoustic neuroma (attached VIII: vestibular branch; present with tinnitus and hearing loss) *extradural *surgical removal is curative

Answer 30

*well-circumscribed, firm gray encapsulated masses *attached loosely to associated nerve without invading *lesion displaces nerve of origin as it grows *can often be resected without sacrificing nerve function

Answer 31

*Schwann cells with spindled/wavy, elongated nuclei *a mixture of dense and loose zones: -Antoni A = dense cellular areas -Antoni B = loose cellular areas