Definition Primary tumors of the brain and spinal cord arising from arachnoidal/pial melanocytic cells Melanocytoma: localized, low-grade, noninvasive Melanoma: malignant, invasive, mitotically active Clinical Features Epidemiology Very rare entities Wide age range, but most occur in the fifth decade You’re…
Pituitary Adenomas Definition A neoplasm of the adenohypophysis Most common tumor of the pituitary gland Clinical Features Epidemiology 10% to 15% of all intracranial tumors Annual incidence: 0.2 to 2.8 cases per 100,000 About 20% to 30% of pituitary adenomas…
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…
Germinoma Definition Radiosensitive neoplasm of young individuals arising in the pineal or suprasellar region with histopathologic and immunohistochemical features similar to testicular seminoma and ovarian dysgerminoma Clinical Features Epidemiology Germinomas account for about 3% of pediatric intracranial tumors 65% of…
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…