Tag Anthony T. Yachnis MD

Hemangioblastoma

Definition Highly vascularized tumor composed of stromal cells and capillaries usually found in the cerebellum, brain stem, or spinal cord Clinical Features Epidemiology 1% to 2% of all intracranial tumors Most common in adults in third to fifth decades; can…

Pineal Parenchymal Tumors

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…

Primary CNS Lymphoma (Pcnsl)

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…

Nerve Sheath Tumors

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 (Tumors of the Meninges)

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%…

Neuronal and Glioneuronal Tumors

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 Tumors

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…

Tumors with Ependymal-Like Features

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…