L0X-Primary and Metastatic tumors of the Nervous System-ChatGPT

What are primary brain tumors

Neoplasms that originate from cells within the CNS such as glia, neurons, and meningeal cells.

What are the most common primary malignant brain tumors in adults

Gliomas, particularly glioblastoma.

What is the most common primary brain tumor overall

Meningioma.

What are metastatic brain tumors

Secondary brain lesions from systemic cancers spreading hematogenously to the CNS.

What are the most common sources of brain metastases

Lung cancer, breast cancer, melanoma, renal cell carcinoma, and colorectal cancer.

What is the most common brain tumor in immunocompromised patients

Primary CNS lymphoma.

What imaging modality is preferred for evaluating brain tumors

MRI with contrast.

What is the hallmark imaging feature of glioblastoma

Ring-enhancing lesion with central necrosis and surrounding vasogenic edema.

What is the typical location of meningiomas

Extra-axial lesions arising from meninges and often attached to dura.

What imaging sign is characteristic of meningioma

Dural tail sign on contrast-enhanced MRI.

What neurologic complication is common with brain metastases

Vasogenic edema causing increased intracranial pressure.

What is the typical pattern of spread in metastatic brain tumors

Multiple lesions at the gray-white matter junction.

What is the most common malignant CNS tumor in children

Medulloblastoma.

What is the most common site of medulloblastoma

Cerebellar vermis.

What is primary CNS lymphoma most commonly associated with

Immunosuppression such as AIDS or post-transplant states.

What is the primary treatment for solitary resectable brain metastasis

Surgical resection followed by radiation.

What is the prognosis of glioblastoma

Poor, with median survival less than two years despite therapy.

What therapies are used for glioblastoma

Maximal surgical resection, radiation, and temozolomide chemotherapy.

What is the typical presentation of brain tumors

Progressive focal deficits, seizures, or signs of increased intracranial pressure.

What are intrinsic malignant brain tumors

Infiltrating glial tumors that arise within brain parenchyma and destroy normal tissue.

What is the most common intrinsic malignant brain tumor in adults

Glioblastoma (WHO grade IV astrocytoma).

What histology defines glioblastoma

Pseudopalisading necrosis and microvascular proliferation.

What syndrome often presents with glioblastoma

Subacute progressive focal neurologic deficit with headache and seizures.

What MRI finding is typical of glioblastoma

Heterogeneous ring-enhancing mass with central necrosis and vasogenic edema.

What is the prognosis of glioblastoma

Very poor, median survival ≈ 15–20 months with current therapy.

What are IDH-wildtype glioblastomas associated with

Primary (de novo) aggressive tumors in older adults with worse prognosis.

What are IDH-mutant gliomas associated with

Secondary gliomas in younger patients with slower course and better outcome.

What chromosomal codeletion is favorable in oligodendroglioma

1p/19q codeletion.

What defines high-grade oligodendroglioma imaging

Cortical-subcortical T2-hyperintense mass with variable enhancement and calcifications.

What neurologic symptom is disproportionately common in oligodendroglioma

Seizures.

What defines anaplastic astrocytoma (grade III)

Infiltrating astrocytoma with mitotic activity but without necrosis or endothelial proliferation.

What defines anaplastic oligodendroglioma

Oligodendroglial tumor with mitoses plus 1p/19q codeletion.

What is primary CNS lymphoma

Malignant B-cell tumor within CNS parenchyma, often periventricular.

What imaging pattern suggests primary CNS lymphoma

Homogeneous enhancing deep periventricular lesions with diffusion restriction.

Why is corticosteroid exposure important in evaluating CNS lymphoma

Steroids cause rapid tumor lysis and can obscure biopsy diagnosis.

What is the standard initial treatment for primary CNS lymphoma

High-dose methotrexate-based chemotherapy ± radiation.

What paraneoplastic complication can intrinsic malignant tumors cause

Increased intracranial pressure and herniation from mass effect and edema.

Meningioma origin

Arachnoid cap cells external to cortex and cranial nerves

Most common primary extracerebral brain tumor

Meningioma

NF2 is strongly associated with what benign CNS tumor

Bilateral vestibular schwannomas

Schwannoma origin cell

Neoplastic Schwann cells of cranial or spinal nerve sheaths

Classical imaging sign of meningioma on MRI/CT

Dural tail with extra-axial enhancing mass

Acoustic neuroma usual clinical presentation

Progressive unilateral sensorineural hearing loss ± tinnitus

Pituitary adenoma classification by size

Microadenoma <10 mm and macroadenoma ≥10 mm

Endocrine-inactive pituitary macroadenoma main symptoms

Mass effect: headache and bitemporal hemianopia

Prolactinoma first-line medical therapy

Dopamine agonists (cabergoline or bromocriptine)

Craniopharyngioma typical anatomic location

Suprasellar region from Rathke pouch remnants

Craniopharyngioma hallmark imaging finding

Calcified cystic–solid suprasellar mass

Vestibular schwannoma characteristic audiometry

Disproportionate speech discrimination loss

Meningioma hormone sensitivity implication

Growth may accelerate in pregnancy or with progesterone exposure

Benign tumor that can compress optic chiasm causing bitemporal hemianopia

Pituitary macroadenoma

Typical growth behavior of meningioma

Slow-growing, expansile, extra-axial with compression rather than invasion

Preferred initial management for small, asymptomatic meningioma

Observation with serial imaging

When to operate on vestibular schwannoma

Large size, brainstem compression, or progressive symptoms

Common late complication of craniopharyngioma treatment

Hypopituitarism and hypothalamic obesity

Most common source of brain metastasis in adults

Lung carcinoma

Most common source of brain metastasis in women

Breast carcinoma

Most common primary to metastasize to posterior fossa

Lung carcinoma

Classic imaging appearance of brain metastasis on MRI with contrast

Multiple ring-enhancing lesions with vasogenic edema

Typical location of metastatic brain lesions

Gray–white junction and watershed zones

Frequency of brain metastases vs primary brain tumors in adults

Metastases are more common than primaries

Most common solitary brain metastasis in adults

Non–small cell lung cancer

Systemic tumor with high predilection for hemorrhagic brain mets

Melanoma renal cell thyroid choriocarcinoma

Usual mechanism of neurologic symptoms in brain metastases

Mass effect edema and increased intracranial pressure

Preferred initial therapy for symptomatic brain mets with edema

High-dose corticosteroids (e.g. dexamethasone)

Role of whole brain radiotherapy (WBRT)

Palliation and control in multiple or diffuse metastatic lesions

Role of stereotactic radiosurgery (SRS)

Local control for small limited number of lesions

Indication for surgical resection in brain metastasis

Single accessible lesion with controlled systemic disease

Brain metastasis prognosis vs primary glioblastoma

Generally worse overall prognosis due to systemic burden

Common pediatric primaries that metastasize to brain

Sarcomas neuroblastoma and germ cell tumors (rare vs adults)

Metastasis that frequently involves leptomeninges

Breast lung melanoma hematologic malignancies

CSF finding in leptomeningeal carcinomatosis

Malignant cells in CSF cytology (often requires repeat taps)

Most common site of extracranial systemic disease when brain mets found

Lung (overt or occult)