CNS Tumors Flashcards
How does the location of brain tumors differ between adults and children?
Adults are usually supratentorial
Children are usually infratentorial (in the cerebellum)
What is the difference between expansile and infiltrative tumor growth?
Expansile: sharp border
Infiltrative: single neoplastic cells spread throughout the parenchyma
What are the major signs/symptoms of a CNS tumor?
Headache/nausea/vomiting from increased ICP Syncope Cranial nerve palsies Focal neurologic deficits Cognitive dysfunction
What are the most common CNS tumors in adults?
Meningioma, schwannoma, glioma
What are the most common CNS tumors in children?
Pilocytic astrocytoma, ependymoma, medulloblastoma
List the types of gliomas
Astrocytoma (most common):
Oligodendroglioma
Ependymoma
List the neuronal and mixed neuronal-glial tumors
Central neurocytoma
Gangliglioma
Dysembryoplastic neuroepithelial tumor (DNET)
List the embryonal tumors
Medulloblastoma
Primitive neuroectodermal tumor (PNET)
Atypical teratoid/rhabdoid tumor (ATRT)
Tumors originating from pituitary gland
Pituitary adenoma
Craniopharyngioma
Tumors of cranial and peripheral nerves
Schwannoma
Neurofibroma
Malignant peripheral nerve sheath tumor (MPNST)
How is the histological malignancy of brain tumors quantified?
WHO grading system: I-IV, IV is most aggressive
Classic finding of pilocytic astrocytoma
Cyst with mural nodule in the cerebellum/brainstem of children and young adults. Histology shows long hair-like bipolar cells and Rosenthal fibers (eosinophilic corkscrew shaped bundle)
What are the 4 levels of glioma grading?
1) Pleomorphism
2) Mitoses
3) Vascular proliferation
4) Necrosis
Classic finding of glioblastoma
Lesion crossing the corpus callosum in butterfly shape with poorly defined borders, central necrosis, red/brown hemorrhage and cystic changes. CT shows ring enhancing mass.
Describe the histological appearance of glioblastoma
Round, ribbon like areas of necrosis with psudopalisading
Classic findings of oligodendroglioma
Calcified tumors of frontal lobe visible on CT. Histology shows perinuclear halos (“fried egg”) and chicken-wire capillary pattern. Neoplastic oligodendrocytes cluster around nuerons to form perineuronal satellitosis.
Difference in appearance between medulloblastoma and retinoblastoma
Both have rosettes, but in MB the central core is composed of delicate neuropil fibrils (Homer-Wright) wheras in RB the cells are arranged around an empty lumen
Classic findings of ependymoma
Most frequent in children, tumor in 4th ventricle causing hydrocephalus. On histology, tumor cells surround vessels to form perivascular pseudorosettes. Can also form true ependymal rosettes with central lumen.
Classic findings of medulloblastoma
Malignant cerebellar tumor in children of neuroectodermal origin. Small blue cells with scanty cytoplasm and dark staining nuclei. MRI shows discrete contrast enhancing mass in the 4th ventricle.
Classic findings of meningioma
Benign tumor of adults (F>M) arising from outside the brain parenchyma. MRI shows dural attachment. Histology shows psammoma bodies and whorls.
Classic findings of craniopharyngioma
Benign childhood tumor deriving from Rathke’s pouch remnants. CT shows suprasellar mass with calcificaitons
Classic findings of schwannoma
Cerebellopontine angle and CN VIII involvement causes loss of hearing and tinnitus. Found bilaterally in NF2. Yellow grossly due to lipid content. Shows alternating Antoni A (compact) and Antoni B (loose) structure with pallisades.
Most common source for metastatic carcinoma to brain
Lung > Breast > Melanoma > Kidney > GI tract
What is Neurofibromatosis type 1?
Familial tumor syndrome with c17 mutation leading to:
Neurofibromas, acoustic schwannomas, optic nerve gliomas, lisch nodules (iris) and cafe-au-lait spots (skin)
Plexiform neurofibroma = NF1
What is Neurofibromatosis type 2?
Familial tumor syndrome with c22 mutation leading to bilateral acoustic schwannomas and multiple meningiomas
What is tuberous sclerosis?
Familial tumor syndrome caused by c9 or c16 mutations leading to hamartomatous lesions in multiple organs.
Triad: adenoma sebaceum, seizures, mental retardation
What is Von Hippel-Landau disease?
Familial tumor syndrome caused by c3 mutation of VHL tumor suppressor. Results in uncontrolled expression of VEGF leading to cerebellar hemangioblastomas. Seen with Renal cell carcinoma.