Laboratory Studies
Patients with cancer are predisposed to medical complications, including bleeding disturbances (hyperviscosity), metabolic disorders (hypercalcemia), and production of excessive hormones (syndrome of inappropriate antidiuretic hormone secretion). Therefore, with clinical suspicion of cancer, obtain routine laboratory studies on admission, including the following:
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Complete blood cell count (CBC)
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Coagulation studies
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Electrolyte levels
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Comprehensive metabolic panel
Imaging Studies
Obtain neuroimaging studies in patients with symptoms suggestive of an intracranial neoplasm (eg, acute mental status changes; new-onset seizures; focal, motor, or sensory deficits, including gait disturbance; suspicious headache; signs of elevated ICP, such as papilledema). Although some tumors exhibit a characteristic appearance, do not make an unequivocal diagnosis based solely on radiologic findings.
Diagnosis of a suspected brain tumor is dependent on appropriate brain imaging and histopathology. Gadolinium-enhanced magnetic resonance imaging (MRI) is the preferred modality because of its resolution and enhancement with contrast agents. If MRI cannot be performed (e.g., in patients with metallic implants, embedded devices, or claustrophobia), head and spine computed tomography (CT) is acceptable, although the resolution is not as high as MRI and it cannot adequately assess lesions in the posterior fossa and spine. [10]
Drawbacks to MRI include incompatibility with certain medical equipment, longer imaging times (increased risk of motion artifact), and poor visualization of the subarachnoid space. Neither CT nor MRI can be used to differentiate tumor recurrence from radionecrosis.
Additional imaging such as magnetic resonance perfusion, magnetic resonance spectroscopy, or fluorodeoxyglucose positron emission tomography may be necessary for diagnosis and staging, and should be ordered only under the direction of the treating physician. [10]
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Brain neoplasms. CT images of several tumor types. Slide courtesy of UMASS Continuing Education Office.
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Brain neoplasms. Colloid cyst of the third ventricle with obstructive hydrocephalus. Image courtesy of Peter Ferrera, MD.
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Brain neoplasms. Occipital lobe glioblastoma with surrounding edema.
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Brain neoplasms. Noncontrast CT scan of a tumor in the region of the posterior corpus callosum.
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Brain neoplasms. Contrast CT scan of the same patient as in media file4. Notice that contrast enhancement brings out detail.
