Childhood Tumors Cerebral hemisphere: Astrocytoma/Anaplastic astrocytoma Ependymoma Oligodendroglioma Corpus Callosum: Astrocytoma/Anaplastic astrocytoma Oligodendroglioma Lipoma Lateral Ventricle: Ependymoma Choroid plexus papilloma Pineal: Germ Cell Neoplasm Cerebellum: Medulloblastoma Astrocytoma Dermoid Third Ventricle: Ependymoma Choroid plexus papilloma Optic Chiasm and Nerve: Astrocytoma Fourth Ventricle : Ependymoma Choroid plexus papilloma Pituitary: Craniopharyngioma Germ Cell Neoplasm Pituitary adenoma Cerebellopntine Angle: Ependymoma Choroid plexus papilloma Brain Stem: Astrocyoma Anaplastic astrocytoma GBM Above Third Ventricle: Pilocytic astrocytoma Fibrillary astrocytoma Oligodendroglioma
	Adult Tumors Cerebral hemisphere: Astrocytoma/Anaplastic astrocytoma/GBM Meningioma Metastatic Carcinoma Vascular Malformation Oligodendroglioma Ependymoma Sarcoma Corpus Callosum: Astrocytoma/Anaplastic astrocytoma/GBM Oligodendroglioma Lipoma Lateral Ventricle: Ependymoma Meningioma Subependymoma Choroid plexus papilloma Pineal: Germ Cell Neoplasm Cerebellum: Hemangioblastoma Metastatic carcinoma Astrocytoma Medulloblastoma Third Ventricle: Colloid Cyst Ependymoma Optic Chiasm and Nerve: Meningioma Astrocytoma Fourth Ventricle : Ependymoma Choroid plexus papilloma Meningioma Pituitary: Pituitary adenoma Craniopharyngioma Meningioma Germ Cell Neoplasm Region of the Foramen Magnum: Meningioma Schwannoma Neurofibroma Cerebellopntine Angle: Acoustic schwannoma Meningioma Epidermoid cyst Choroid plexus papilloma Glomus jugulare tumor Brain Stem: Astrocyoma Anaplastic astrocytoma GBM Above Third Ventricle: Astrocytoma/Anaplastic astrocytoma/GBM Oligodendroglioma Ependymoma Pilocytic astrocytoma

Neuronal Responses to Injury
Wallerian Degeneration - breakdown of axon distal to injury
Central Chromatolysis - neuronal cell body clearing proximal to injury (may be reversible)
Retrograde Degeneration - neuron undergoes atrophy when the distal axon is damaged
Trans-synaptic Degeneration - neuron undergoes atrophy when main synaptic input is lost
Causes of Neuronal injury: anoxic/ischemic, excitotoxicity, apoptosis, metabolic storage disease
Demyelination: (stain black with Marchi's or Sudan Black; unstained with Weigert-Pal or Loyez) Primary - specific destruction of myelin (precedes axon damage) Secondary - follows nerve cell death and axon destruction
CELL	IMMUNOHISTOCHEMISTRY	REACTION TO INJURY
Neuron	Neurofilament, Synaptophysin, NSE	Central chromatolysis, Wallerian degeneration, neuronopathy, retrograde degeneration, Trans-synaptic degeneration, Ischemia
Astrocyte	GFAP, Vimentin	Proliferation, Hypertrphy (gemistocyte), Gliosis
Oligodendrocyte	Leu 7, galactocerebroside	Swelling, Proliferation
Ependyma	Weak GFAP	Atrophy, Loss (granular ependymitis)
Microglia	B cell and Macrophage markers	Proliferation, microglial nodule, rod cell shape