Online module: Intracranial Mass Lesions

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Online moduleIntracranial Mass Lesions
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Couple of quick things

• As you can imagine, this is a HUGE topic that
  encompasses parts of Neurosurgery that some
  individual develop subspecialties within!
• Dont fret. The point here is to develop a
  general understanding of presentation, what clues
  the presentation(s) can provide as to the
  diagnosis, what you should or should NOT do, etc.

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Intracranial Mass Lesions Differential
Considerations

• Primary Brain Tumor/Lesion
• Including non-neoplastic cysts, congenital, etc.
• Metastatic Lesion
• Trauma (see module on Neurotrauma)
• Infection
• Vascular (see module on Neurotrauma)
• Including aneurysms, AVMs, stroke, etc.
• Inflammatory

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Clues to diagnosis

• Have an idea of those differential considerations
  in your mind, to choose from when a patient
  presents.
• Mass lesions can present any of a number of
  different ways, but clues to the diagnosis is
  often times hidden within the manner in which
  they present.

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Tumors

• Mass effect from tumor itself
• Presentation is function of brain compression
• A large frontal convexity meningioma may cause
  arm weakness, slurred speech, gradual confusion,
  etc.
• Mass effect from irritation of brain
• Presentation is function of edema/swelling around
  tumor
• A small focus of lung cancer, for example, can
  incite a large surrounding area of
  edema/irritation.

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Tumors

• Tumors usually present insidiously.
• Most common presentation of brain tumor is
  progressive neurologic deficit, particularly
  motor weakness.
• Seizures in 26 (especially supratentorial) - any
  first time seizure in an adult needs thorough w/u
  to rule out brain lesion.
• Posterior fossa tumors commonly present with
  increased ICP and other symptoms secondary to
  hydrocephalus.

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Metastatic Brain Lesion

• Cerebral metastasis is initial presentation in
  15 of patients with previously-unknown cancer.
• Lung cancer by far most common, followed by
  breast, kidney, and GI.

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Metastatic Brain Lesion

• Question surgery or not?
• Very important to consider patients functoinal
  status at time of presentation. Poor functional
  status generally poor surgical candidate.

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Surgery for metastatic disease

• Solitary lesion
• Obtain tissue for diagnosis (primary unknown)
• Symptomatic and/or life-threatening lesion
• Lesion is accessible to surgical removal (i.e.
  not buried beneath the motor strip)
• Good functional status, good relative prognosis
• Multiple lesions
• Palliative (a lesion is symptomatic/life-threateni
  ng)
• Obtain tissue for diagnosis

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Intracerebral Infection/Abscess

• Risk factors Dental abscess, pulmonary abscess,
  immunocompromised state, IV drug use, pulmonary
  A/V fistulas, penetrating head trauma, etc.
• Presentation is usually secondary to symptoms of
  increased ICP, and more acute than tumors but not
  sudden. Seizures are common, as are focal
  neurological deficits.
• Fever, abnormal labs (ESR, CRP) are clues.

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Inflammatory lesions

• Classic presentation would be middle-aged female
  with hx of MS who presents with 4 to 5 days of
  new progressive neurologic deficit.
• No fevers, etc.
• Brain imaging shows one or multiple lesions.
• Tumefactive MS can be very difficult to
  distinguish from tumor, especially glioma.

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Intracranial Mass Lesions

• Trauma patients would present with appropriate
  history, or physical exam findings c/w that.
• Vascular patients present with SUDDEN changes in
  mentation or neurological status, either from
  stroke, hemorrhage, etc.
• Important thing to always keep in mind in cases
  of space-occupying lesions in the brain Do not
  rush to LP!!! You can cause tonsillar herniation!

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Summary

• Keep in mind these six possibilities for
  patients presenting with head lesions (Primary
  brain tumor, metastatic disease, trauma,
  infection, vascular, inflammatory), and compare
  the logical presentation for each with your
  patients presentation to help narrow down your
  differential.