Chapter 20-12: Intracranial Neoplasms

TEXTBOOK PRESENTATION

Brain tumors classically present with progressive morning headaches associated with focal neurologic deficits.

DISEASE HIGHLIGHTS

1. Brain tumors are classified as metastatic, primary extra-axial, and primary intra-axial.

2. The relative frequencies of types of tumors within each type are listed below:

   1. Metastatic

      1. Lung, 37%

      2. Breast, 19%

      3. Melanoma, 16%

   2. Primary extra-axial

      1. Meningioma, 80%

      2. Acoustic neuroma, 10%

      3. Pituitary adenoma, 7%

   3. Primary intra-axial

      1. Glioblastoma, 47%

      2. Astrocytoma, 39%

3. Metastatic tumors are about 7 times more common than primary tumors. (Thus, a new headache in a patient with known malignancy should be taken very seriously.)

4. Intracranial neoplasms generally present with seizure; focal neurologic signs; or signs of increased intracranial pressure, such as headache.

5. Although the presenting symptoms vary with type of tumor, the most common symptoms are

   1. Headache (about 50% of the time)

   2. Seizure

   3. Hemiparesis

   4. Change in mental status

EVIDENCE-BASED DIAGNOSIS

1. History

   1. The history of a patient’s headache is not particularly helpful in making a diagnosis of intracranial neoplasms.

   2. One very good report retrospectively studied 85 patients with brain tumors. The symptoms were nonspecific.

      1. 60% of patients had headaches.

      2. Only 2% of patients had headache as the solitary presenting feature

      3. 40 patients had preexisting headache disorders but 82.5% of these patients had a change in their headache pain

      4. Only 6% were associated with laying supine (a symptom classically ascribed to brain tumors).

      5. 40% of patients met the criteria for tension headaches.

      6. Headaches were frequently dull of moderate intensity and pain was controlled with nonopiate pain medications.

In patients without a history of cancer, brain tumors almost never present as an isolated headache.

Brain tumor headaches are nonspecific. A patient with a new headache and a preexisting cancer that could potentially metastasize to the CNS should undergo imaging.

2. Neuroimaging

   1. Contrast-enhanced CT

      1. A reasonable choice for screening patients in whom there is a low suspicion.

      2. The sensitivity of a contrast-enhanced CT for intracranial neoplasm is around 90%.

   2. MRI with contrast is the procedure of choice for imaging brain tumors. The sensitivity of MRI is nearly 100%, and the detail provided often suggests a likely pathology.

TREATMENT

1. The treatment of brain tumors depends on the pathology.

2. Importantly, patients with signs of increased intracranial pressure or seizure should be hospitalized immediately enabling both rapid diagnosis and treatment.