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132 Neuro: Neoplasms & how to be a better student

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Neurologic Neoplasms

Benign Neurologic Neoplasms

Meningioma

  • Most common benign intracranial tumor; originates from meninges (arachnoid cells)
  • Slow-growing, frequently calcified

Clinical Presentation

  • Often asymptomatic or gradual-onset headaches, seizures, focal deficits

Labs, Studies, and Physical Exam Findings

  • MRI: extra-axial lesion with dural attachment (“dural tail sign”)
  • CT: often calcified

Treatment

  • Surgical resection if symptomatic; observation if incidental

Schwannoma (Acoustic Neuroma)

  • Originates from Schwann cells, commonly affects CN VIII at cerebellopontine angle

Clinical Presentation

  • Progressive unilateral hearing loss, tinnitus, balance issues
  • Possible facial nerve involvement (CN VII)

Labs, Studies, and Physical Exam Findings

  • MRI: enhancing lesion at cerebellopontine angle

Treatment

  • Surgical resection, stereotactic radiosurgery, or observation if small

Pituitary Adenoma

  • Benign anterior pituitary tumor; may be hormone-secreting or nonfunctional

Clinical Presentation

  • Endocrine abnormalities (prolactinoma, acromegaly, Cushing’s disease)
  • Bitemporal hemianopsia from optic chiasm compression

Labs, Studies, and Physical Exam Findings

  • MRI: sellar mass compressing optic chiasm
  • Hormone level assessment (prolactin, GH, ACTH)

Treatment

  • Prolactinoma: Dopamine agonists (Cabergoline)
  • Surgical resection if visual or hormonal disturbances

Malignant Neurologic Neoplasms

Glioblastoma Multiforme (GBM)

  • Most common and aggressive primary CNS malignancy; Grade IV astrocytoma

Clinical Presentation

  • Rapid onset and progression of headaches, seizures, focal deficits, cognitive changes
  • Increased ICP: nausea/vomiting, papilledema

Labs, Studies, and Physical Exam Findings

  • MRI: irregular, infiltrative lesion with central necrosis (“butterfly” glioma crossing corpus callosum) and extensive edema

Treatment

  • Surgical debulking, radiation, chemotherapy (Temozolomide)
  • Prognosis poor (median survival 12-15 months)

Medulloblastoma

  • Malignant pediatric brain tumor located in cerebellum; commonly in posterior fossa

Clinical Presentation

  • Symptoms due to obstructive hydrocephalus: headache, vomiting, ataxia, gait instability
  • Increased ICP: papilledema, altered mental status

Labs, Studies, and Physical Exam Findings

  • MRI: enhancing mass in posterior fossa; obstructive hydrocephalus

Treatment

  • Surgical resection, radiation, chemotherapy
  • Prognosis varies with subtype and resection completeness

CNS Lymphoma (Primary CNS Lymphoma)

  • Aggressive malignancy primarily affecting immunocompromised patients (HIV/AIDS, post-transplant)

Clinical Presentation

  • Rapid cognitive decline, focal neurological deficits, seizures
  • May present with constitutional “B symptoms” (fever, weight loss, night sweats)

Labs, Studies, and Physical Exam Findings

  • MRI: multifocal, enhancing lesions; periventricular distribution common
  • CSF cytology may confirm lymphoma cells

Treatment

  • High-dose IV methotrexate-based chemotherapy; radiation therapy
  • Steroids used cautiously (can mask diagnosis on imaging)

Metastatic Brain Tumors

  • Most common intracranial malignancy in adults; primary cancers: lung, breast, melanoma, renal

Clinical Presentation

  • Rapid-onset neurological deficits dependent on tumor location
  • Symptoms often multifocal; increased ICP symptoms common (headache, nausea/vomiting, seizures)

Labs, Studies, and Physical Exam Findings

  • MRI: multiple ring-enhancing lesions at gray-white junction with vasogenic edema

Treatment

  • Corticosteroids for symptomatic edema (Dexamethasone)
  • Radiation (whole-brain or stereotactic), surgical resection for single metastasis, chemotherapy

Key Differentiators

Between benign tumors:

  • Meningioma: dural-based, calcified, typically supratentorial; often asymptomatic
  • Schwannoma: affects CN VIII; hearing loss and balance issues
  • Pituitary adenoma: visual field deficits (bitemporal hemianopsia), hormone abnormalities

Between malignant tumors:

  • Glioblastoma: aggressive, rapidly progressive, butterfly lesion crossing midline
  • Medulloblastoma: pediatric, cerebellar/posterior fossa mass with obstructive hydrocephalus
  • CNS Lymphoma: immunocompromised patient, multifocal periventricular lesions, rapid cognitive changes
  • Metastases: multiple lesions at gray-white junction, known primary cancer elsewhere

Benign vs. Malignant:

  • Benign: slow growth, defined margins, minimal edema, better prognosis
  • Malignant: rapid progression, infiltrative margins, significant edema, poor prognosis