Brain Tumors Flashcards
Extra axial/extra parenchymal
Meninges
Intra-axial/intra-parenchymal
Brain
Carcinogenesis
Cellular process by which normal cells become cancerous
- things going awry during cell cycle and the cell will continuously undergo ell division
- oncogenes favor formation of tumors
- tumor suppressor genes: supress entry into cell cycle
- tumor is when cells have aggregated into a single mass
- stop performing normal function usually, but sometimes can go into overdrive. Usually loss of normal function
Exceptions of post natal CNS neurons not enter mitosis
- only a few isolated regions of the CNS have neural stem cells that continue to produce new neurons (neuro genesis), speicifically in the olfactory bulb and ventricular zone of the CNS (deepest cell layers next to ventricular system)
- glia retina the ability to enter the cell cyl thrghouout adulthood
- neuroantaotmical hotspots for some tumor types e.g. medullablastoma formation in deep white matter of cerebellum, olfactory groove meningioma
Meningioma SJS
Several common hot spots
Dura mater
Nerublastoma
From neural stem cells
Astrocytoma or gliobastoma
Astrocytes can develop these
Oligodendroglioma
In cerebral white matter
Neuromas or schwannoma
From Schwann cells in the PNS
Ependymomas
From ependymal cells lining the ventricular system
Choroid plexus cancer
Forms benign or malignant tumors (papilloma or carcinoma)
Pituitary ademona
Pituitary tumor can grow out of sella turcica into the brain
Pineal tumor
Compression of dorsal midbrain (parinauds syndrome)
Meningioma hot spots in the dura mater
Flax cerebri External to frontal lobes Olfactory groove over ethmoid bone Patrons ridge of sphenoid bone Clivus region
Astrocytoma location
In grey and whit matter, can origination essentially from anywhere
Mass effect
Increased mass/volume and intracranial pressure
Herniations syndromes
Tumors and angiogenesis
Increased vascularization
- new blood vessles can bleed, causing hematoma
- bleeding can induce seizure activity or cause neurodegeneration locally
- tumors can also undergo necrosis of tumor cells
Vasogenic edmea
Swelling due to accumulation of extracellular fluid
Cytotoxic edema
Swelling of dying cells
Paraneoplastic syndromes
Auto-immun parthology typically caused by antibodies targeted agaisnt the tumor but cross reacts with normal antigens in normal brain tissue, leads to damage or neurodegeneraiton