Ependymoma Definition A slowly growing tumor generally arising in the central region of the spinal cord in adults or a ventricle in children and adults Most correspond to World Health Organization (WHO) Grade II; anaplastic ependymomas are WHO Grade III…
Pleomorphic Xanthoastrocytoma (PXA) Definition A superficially located astrocytic neoplasm usually arising in children and young adults; circumscribed tumor with reticulin deposition, significant pleomorphism, and favorable prognosis Most correspond to World Health Organization (WHO) Grade II; anaplastic PXAs are WHO Grade…
Oligodendroglioma Definition A diffuse infiltrating glioma of adults consisting of cells resembling oligodendroglia, often with chromosomal deletions of 1p and 19q; typically located in the cerebral hemispheres World Health Organization (WHO) Grade II Clinical Features Epidemiology Constitute 3% of primary…
Diffuse Astrocytoma Definition Infiltrating glial neoplasm with astrocytic features, typically with some degree of pleomorphism, increased cellularity and slow growth; also known as low-grade diffuse astrocytoma World Health Organization (WHO) Grade II Clinical Features Epidemiology Peak incidence in fourth decade,…
Epidural Hematoma Definition Collection of blood within a potential space between skull and dura mater. Clinical Features Epidemiology Occurs in 1% to 4% of imaged head trauma patients Seen in 5% to 15% of patients with fatal head injuries Age…
Contusion/Laceration (Including Coup and Contrecoup Lesions) Definition Direct injury to surface of brain parenchyma, usually involving the cortical gray matter Contusion: a “bruise” of the brain with intact pia mater Laceration: tearing of brain tissue with breached pia mater Clinical…
Cerebral Amyloid Angiopathy Definition Vasculopathy arising from deposition of Aβ-amyloid peptide within walls of meningeal and superficial cortical blood vessels, which can lead to acute focal, multifocal, or lobar hemorrhages; a small subset of patients develop an intense inflammatory response…
Giant Cell Arteritis Definition Panarteritis affecting medium-sized and large extracranial branches of the aorta; most common primary vasculitis to affect the nervous system Clinical Features Epidemiology Incidence: 15 to 25 cases per 100,000 Peak incidence in individuals 75 to 85…
Arteriovenous Malformations (AVM) Definition Abnormal collection of thick-walled blood vessels with intervening gliotic brain tissue; arterial blood flows directly into draining veins without interposed capillary beds in this “high-flow” vascular malformation Clinical Features Epidemiology AVMs are congenital lesions Prevalence is…
Saccular (“Berry”) Aneurysms Definition A localized dilatation or ballooning of a cerebral artery that lacks an internal elastic lamina and has disrupted muscular layers; subarachnoid hemorrhage (SAH) commonly occurs with aneurysm rupture; intraventricular hemorrhage may also occur; synonyms: saccular aneurysm,…