Pineocytoma Definition WHO Grade I primary pineal parenchymal tumor; a well-circumscribed, slow-growing tumor composed of small uniform pinealocyte-like cells Clinical Features Epidemiology Account for 14% to 60% of pineal parenchymal tumors Age ranges from 10 to 65 years; mean age…
Definition Malignant lymphomas arising independently within the CNS without evidence of systemic lymphoma; most PCNSLs are aggressive B-cell lymphomas Clinical Features Epidemiology Comprise between 1% to 5% of primary brain tumors Peak incidence in immunocompetent individuals between 55 to 75…
Schwannoma Definition World Health Organizatin (WHO) Grade I encapsulated nerve sheath tumor composed of differentiated Schwann cells; associated with neurofibromatosis type 2 or schwannomatosis Clinical Features Epidemiology 8% to 10% of all intracranial tumors Age range: 10 to 90 years…
Meningiomas: Overview and General Characteristics Definition Neoplasms arising from meningothelial (arachnoidal) cells; are usually attached to the inner surface of the dura mater (dural-based tumors) Clinical Features Epidemiology Comprise about 25% to 30% of primary intracranial tumors Incidental finding 1.4%…
Medulloblastoma Definition Malignant, embryonal tumor arising primarily in the posterior fossa of children Clinical Features Epidemiology Most common primitive neuroepithelial tumor (PNET) in CNS; 0.5 per 100,000 Peak incidence: 5 to 10 years; adults cluster in 30s 20% of brain…
Ganglion Cell Tumors Definition Well – differentiated tumors of the CNS with mature neurons (ganglion cells) as a defining feature: includes ganglioglioma (ganglion cell tumor with a low-grade glial element), gangliocytoma (without a glial element), and anaplastic ganglioglioma (ganglion cells…
Choroid Plexus Papilloma Definition Intraventricular papillary neoplasm; most common in children World Health Organization (WHO) Grade I Clinical Features Epidemiology Comprise 0.3% to 0.6% of brain tumors; 2% to 4% of pediatric brain tumors Most common in children under the…
Angiocentric Glioma Definition Low-grade glial neoplasm (WHO Grade I) arising in childhood and typically associated with epilepsy; key pathologic features include angiocentric growth and monomorphous spindle cells; also called monomorphous angiocentric glioma and angiocentric neuroepithelial tumor Clinical Features Epidemiology Rare…
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…