Brain tumor

A brain tumor is any intracranial mass created by an abnormal and uncontrolled growth of cells either normally found in the brain itself: neurons, glial cells (astrocytes, oligodendrocytes, ependymal cells), lymphatic tissue, blood vessels), in the cranial nerves (myelin producing cells Schwann cells), in the brain envelopes (meninges), skull, pituitary and pineal gland, or spread from cancers primarily located in other organs (metastatic tumors).

Diagnosis

Although there is no specific clinical symptom or sign for brain tumors, slowly progressive focal neurologic signs and signs of elevated intracranial pressure, as well as epilepsy in a patient with a negative history for epilepsy should raise red flags. However, a sudden onset of symptoms, such as an epileptic seizure in a patient with no prior history of epilepsy, sudden intracranial hypertension (this may be due to bleeding within the tumor, brain swelling or obstruction of cerebrospinal fluid's passage) is also possible.

Related Topics:
Epileptic seizure - Intracranial hypertension - Cerebrospinal fluid

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Imaging plays a central role in the diagnosis of brain tumors. Early imaging methods—invasive and sometimes dangerous—such as pneumoencephalography and cerebral angiography, have been abandoned in recent times in favor of non-invasive, high-resolution modalities, such as computed tomography (CT) and especially magnetic resonance imaging (MRI). Benign brain tumors often show up as hypodense (darker than brain tissue) mass lesions on cranial CT-scans. On MRI, they appear either hypo- (darker than brain tissue) or isointense (same intensity as brain tissue) on T1-weighted scans, or hyperintense (brighter than brain tissue) on T2-weighted MRI. Perifocal edema also appears hyperintense on T2-weighted MRI. Contrast agent uptake, sometimes in caracteristic patterns, can be demonstrated on either CT or MRI-scans in most malignant primary and metastatic brain tumors. This is due to the fact that these tumors disrupt the normal functioning of the blood-brain barrier and lead to an increase in its permeability.

Related Topics:
Pneumoencephalography - Angiography - Computed tomography - Magnetic resonance imaging - Contrast agent - Blood-brain barrier - Permeability

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Electrophysiological exams, such as electroencephalography (EEG) play a marginal role in the diagnosis of brain tumors.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

The definitive diagnosis of brain tumor can only be confirmed by histological examination of tumor tissue samples obtained either by means of brain biopsy or open surgery. The histologic examination is essential for determining the appropriate treatment and the correct prognosis for each individual patient.

Related Topics:
Diagnosis - Histological examination - Tumor - Tissue - Biopsy - Surgery - Prognosis

~ ~ ~ ~ ~ ~ ~ ~ ~ ~