Brain tumor

The CNS (central nervous system) is affected by a large number of primary brain tumors and by metastases of cancers originating from other organs.

There are approximately 25,000 new cases of primary brain tumors and 200,000 new cases of brain metastatic cancers per year in the US.

There area approximately 85,000 individuals in the US diagnosed with primary brain tumor each year, of which approximately 29% are malignant.

Approximately 80 to 85% of malignant brain tumors in adults are gliomas which diffusely infiltrate the brain parenchyma.

Brain tumors I have a high morbidity and have complications that rarely affect other anatomical locations.

Less than 5% of malignant brain tumors are related to a family history, or have a cancer predisposition syndrome.

Primary malignant brain tumors range from pilocytic astrocytomas, which are very uncommon, noninvasive, and surgically curable, to glioblastoma the most common malignant brain tumor in adults, which is highly invasive and virtually incurable.

Prior exposure to ionizing radiation to the CNS, usually during treatment for another cancer, such as childhood leukemia, is a risk factor for brain tumors.

Exposure to low frequency electromagnetic fields is not an established risk factor for brain tumors, and there is not high-quality evidence demonstrating in association between cellular telephone use and brain tumor formation.

Headache occurs in nearly 50% of patients with a newly diagnosed brain tumor.

Patients with rapidly growing tumors may develop increased intracranial pressure and present with nausea, vomiting, or fatigue.

Transient increases in intracranial pressure can cause episodic loss of consciousness, and may be mistaken for seizures.

Patients with metastatic brain disease may have a rapidly progressive disease.

Patients with brain metastases may have one or many lesions, and they may have a malignancy that is responsive to, or, highly resistant to radiationtherapy or chemotherapy.

Neurologic symptoms and signs from brain tumors relate to the anatomical area of CNS involvement.

Tumors affecting the frontal lobes  may cause lack of initiative and difficulties with processing information and responding appropriately to the environment.

Tumors in the dominant hemisphere may present with speech, difficulty, and non-dominant tumors may have more subtle symptoms of spatial, distortion and constructural apraxia.

Anosognosia, the inability to recognize one’s deficits, may contribute to delayed symptom reporting.

Cranial neuropathies due to leptomeningeal dissemination of disease, or increased intracranial pressure can present with ocular palsies, hearing loss, or dysphagia.

As many as 74% of patients with lower grade gliomas present with seizures.

Primary central nervous system lymphoma preferentially affects deep matter structures, and about 40% exhibit behavioral cognitive changes.

Patients with primary CNS lymphoma, who had an involvement of the vitreoretinal space, which is about 25% of patients, may present with blurred vision or floaters.

CNS tumors are associated with symptoms that range from: seizures, fatigue, impaired memory, changes in behavior or cognition, anxiety, depression impaired mobility, impaired speech, impaired comprehension, visual impairment as well as complications of intracerebral edema, infections, endocrinopathies. venous thrombosis.

Glioblastomas are highly associated with thrombosis ranging from 10 to 40%.

Brain metastasis are less strongly associated with the thromboembolism: approximately 10% with lung cancer and lower with melanomas, renal cell cancer, breast cancer or colorectal cancer.

No symptoms or clinical signs are specific to primary or secondary brain tumors.

Focal for lateralized effects of brain tissue destruction include hemiparesis, aphasia, and visual defects.

Symptoms often presents subacutely and show a progressive course over days or weeks.

Leptomeningeal disease is associated with multifocal signs and symptoms.

Generally, brain tumors are associated with: headaches nausea and vomiting, mental changes, gait difficulties, cranial nerve palsies, focal or radiating neck and back pain.

Symptoms of increased intracranial pressure are headache, with or without nausea and vomiting, cognitive impairment, gait disturbances, and personality changes.

Brain tumor symptoms are caused by direct pressure of the tumor, edema, impairment  of CSF circulation and secondary hydrocephalus.

Generalized headache or unilateral throbbing may be accentuated after supine positioning, in the morning, and improved when upright during the day.

Prevalence studies estimated that there were 138,054 patients with a diagnosis of the primary malignant brain tumor in the US in 2010.

Approximately 13,000 deaths per year in the U.S.

Malignant ((glioma))s  are the most common type of primary malignant brain tumor, accounting for 80% of patients in the annual incidence of 5.26 per 100,000 population or 17,000 new cases a year.

5-year survival rates for malignant brain tumors are the third lowest among all types of cancer.

Prognosis depends on locale of the tumor, but more importantly on the histology.

Commonly have different grades within one brain lesion specimen.

Primary and metastatic tumors have significant areas of hypoxia which is associated with poorer prognoses.

Approximately 60% of primary CNS tumors are gliomas with about 65% high-grade Grade III and Grade IV lesions.

In children under the age of 15 years 5-year survivals are 73.3%.

5-year survival rate for children with low-grade cystic cerebeller astrocytomas greater than 90%.

5-year survival rate for children with high-grade diffuse brainstem gliomas is less than 10%.

Incidence of primary tumors of the central nervous system about 11 per 100,000 persons per year.

Most common symptoms include headache, nausea, vomiting, anorexia, dizziness, drowsiness, focal neurological deficits determined by size and site of the tumor and can affect motor/sensory functions.

Headaches occur in 60% of patients who have a brain tumor.

Seizures may occur in up to 50% of patients.

Cognitive impairment and personality changes may occur.

Headaches are usually made worse by the Valsalva maneuver, and upon awakening, reflecting increases in intracranial pressure.

Headaches may be associated with papilledema, focal neurologic abnormalities, nausea or seizures.

Ionizing radiation only unequivocal risk factor identified for glial and meningeal neoplasms.

Test of choice for diagnosis is and MRI of the brain with gadolinium enhancement.

A normal contrast-enhanced MRI scan essentially rules out the possibility of a brain tumor.

Glioblastomas typically show contrast enhancement on T1-weighted sequences;T2 – weighted/fluid-attenuated inversion recovery (T2/flare) reveals hyperintense cerebral edema; Central necrosis, and signs of local mass effect may also be present.

Lower grade gliomas are often hypodense on T1 weighted imaging and hyperintense on T2/flare.

Primary CNS lymphoma may be multifocal and demonstrate homogeneous enhancement and fusion restriction on the fusion, weighted imaging.

Glial tumors-histological features of the tumor and the patient’s age and performance status are major prognostic factors and have more influence than any specific therapy on the outcome.

Cognitive defects shortly after radiation therapy are due to deficits present before treatment and are probably caused by the disease itself.

Cognitive impairment associated with primary or metastatic lesions of the brain and from treatments, including radiation, occurs in 10% of patients developing progressive dementia and 50-90% showing cognitive deficits by sensitive testing.

Only one third of children with benign brain tumors treated with surgery alone survive without neurological deficits.

Prophylaxis against seizures with antiepileptic drugs is not supported by the literature.

Antiepileptic drugs are used with caution in brain tumor patient’s because of multiple potentially serious interactions with chemotherapy or corticosteroids (Glantz MJ).

The use of glucocorticoids improved edema, mass effect and decrease his contrast enhancement, and these changes may be related to the induction of vasoconstriction and reduction in vascular permebility (Piette C, Jarden JO, Leenders KL).

The use of steroids in patients with brain tumors should be limited to those with symptomatic mass effect or cerebral edema.

Dementia may occur in children below the age of 2 years that have been treated with cranial or craniospinal radiation.

Children treated for brain tumors are 10.8 times less likely to be employed and 28.8 times less likely to be able to drive a car than their non-treated siblings.

Cognitive problems in children appear 2 or more years after completion of treatment.

Tumor tissue is required to establish the diagnosis.

Procedures are typically performed under general anesthesia and preservation of neurologic function with maximal safe  surgical resection is a priority.

Patients may undergo awake craniotomies with repetitive neurologic assessment during the resection.

When esection is not feasible, a tumor biopsy is performed.

Accurate grading of CNS tumors can estimate patient prognosis and requires integration of histological features and molecular abnormalities.

Astrocytomas with mutations of IDH 1 or IDH 2 and homozygous loss of cyclin dependent kinase, inhibitor 2A and B, are considered grade 4, even if they lack histological features of a grade 4 tumor.