Brain Tumors

Brain tumor is any intracranial tumor caused by uncontrolled cell division, either within the brain, cranial nerves, the mater, the skull, the pituitary and pineal gland or metastatic tumor. Primary brain tumors in children are usually found on the posterior part of the skull and in adults are usually found in the frontal cerebral hemispheres and can also develop in any part of the brain.

Brain tumors are divided into two categories, primary and secondary.

Primary tumors  appear by themselves , without metastasis from another part of the body.

• Secondary tumors are metastatic cancer cells which have spread from another organ of the body

Primary brain tumors develop from the proliferation of brain cells. Secondary brain tumors are more frequent than primary brain tumors. In children, most tumors are primary. In adults, the opposite is true, in other words most tumors are metastasis of cancers which manifested elsewhere in the body.

Distribution and incidence rates by category:

Primary tumors

• Neuroectodermal:  which represent 50% of all brain tumors include all astrocytoma tumors (glioblastoma, ependymoma, oligodendrogliomas, medulloblastoma)
• Meningiomas: 20%
• Pituitary: 8-9%
• acoustic neuromas: 4-5%

Secondary tumors

10%  of secondary tumors can be surgically treated.

The symptoms which primary and secondary tumors provoke usually affect functions such as sight, hearing, speech, memory, movement, balance, behavior and mental state.

Specifically the most basic symptoms are:

• Severe headache
• Vision problems (blurred, double vision)
• Speech and Hearing Difficulties
• Problems balancing, walking or with posture
• Vomiting
• Loss of sensation and/or movement
• Confusion, difficulty to concentrate.
• Behavioral changes.
• Seizures
• Amnesia
• cranial nerves palsy
• Muscle weakness of one limb or one side

Diagnosis

Although there is no specific symptom for brain tumors, the diagnosis usually involves a complete neurological examination and based on the findings the doctor may recommend any of the following tests:

• Computed tomography (CT scan)
• Magnetic resonance imaging (MRI)
• Magnetic resonance spectroscopy(MRS)
• Magnetic resonance angiography(MRA)
• Digital subtraction angiography(DSA) 4 cerebrovascular
• PET SCAN
• Magnetic Tractography (MR-Tractography)
• Functional Magnetic Resonance Imaging( fMRI)

Diagnosis is  only definite after histological examination of tumor specimens. The samples are obtained either through biopsy or surgery.

Brain tumors are differentiated by their clinical, imagery, surgical & pathologoanatomical characteristics.

Unlike other cancers, the possibility of total or partial removal and therefore the temporary or permanent outcome depends both on the histological texture and the detection of Neoplasia. Surgery of patients with benign tumors in inaccessible or hardly accessible areas is always a challenge as is surgery of patients with malignant tumor in accessible areas  where the relapse rate  is high despite radical resection. It is understandable that apart from the histological texture of the tumor, the location and size of the lesion are the basic parameters which determine the possibility of total or partial resection and therefore the temporary or permanent cure.

Surgical Indications:

All brain tumors should be treated either surgically or with radiation or chemotherapy or radiosurgery.

Accessible brain tumors depending on the type of tumor can be fully removed in which case cure is complete and permanent. For surgically inaccessible tumors such as is usual with  brain stem gliomas  stereotactic biopsy method is used to obtain pathological tissue.  Radiotherapy and radiosurgery treatments bring relief and the prognosis is usually grave.

Conslusively, Neuroectodermal tumors are treated  with surgery, radiotherapy, radiosurgery and chemotherapy.

For menigiomas surgical removal is usually sufficient and the necessity for additional therapy with radiotherapy is rare. Pituitary tumors are treated surgically either by transphenodial or transcranial surgery and where necessary, further treated with radiosurgery.

Furthermore, acoustic neuromas are surgically treated and in cases where total resection is not possible, in order to prevent any cerebral palsies of the nerves additional radiotherapy and radiosurgery is required.

After surgery of metastatic tumors, additional radiotherapy and chemotherapy are necessary for the primary site as well.