BRAIN TUMOR

What is it?

Brain neoplasms are a diverse group of primary (nonmetastatic) tumors arising from one of the many different cell types within the central nervous system.

Malignant brain tumors are defined by histopathologic features and a rapidly progressive pattern of growth

Glioblastoma is the most common primary brain tumor in adults, accounting fo 50% to 60% of primary brain tumors

Pathophysiology

Nervous system tumors are clonal proliferations that develop secondary to changes in key growth regulatory genes

These genetic changes result in powerful growth advantages that enable the cells to priloferate, evolve, and disseminate

The etiologies of brain tumors remain unknown. To date, only radiation and hereditary predisposition are

clearly implicated as etiological factors The WHO classification currently lists more than 100

types of nervous system tumors and their variants This classification system allows for consideration of key

clinical and imaging characteristics which can narrow the differential diagnosis to only a few common possibilities

Pathophysiology

Only about 5% of primary brain tumors have known hereditary factors Li-Fraumeni syndrome, p53 defects, neurofibromatosis 1

(NF1) and 2 (NF2), tuberous sclerosis, von Hippel-Lindau disease, Turcot’s syndrome, and familial polyposis

Meningiomas Strongest genetic link has been associated with NF2, an

almost 50% incidence Known to express estrogen and progesterone receptors. High incidence of somatostatin receptors has also been found Significance of these findings is uncertain but has led to

diagnostic tests and treatment strategies Radiation is only definite cause

Oligodendrogliomas Viral infections (specifically the JC virus) has been implicated,

but data are inconclusive

Incidence

Glioblastomas occur in approximately 2-3 cases/100,000 persons Most commonly diagnosed primary brain tumor of

adults is glioblastoma mulitforme (grade IV) Slightly more common in whites than blacks,

Latinos, and Asians Slightly more common in men than women with

a male:female ration of 3:2 Peak incidence is between 45 and 70 years. Approximately 10% of glioblastomas occur in

children

Risk Factors

Prior radiation may increase risk for primary brain tumor

Signs and Symptoms

Headache Most common presenting complaint – reported by

approximately 50% of the patients Seizures (occur in 30%-60% of cases) Signs and symptoms of hydrocephalus (headache,

vomiting, clouding of consciousness, papilledema) Memory loss Focal motor weakness Visual changes Language deficits Cognitive disturbances Memory changes

Clinical Presentation

Worsening headache Present for weeks to months Classic triad of brain tumor headache:

Sleep disturbances Severe pain Nausea and vomiting

Headache is often bilateral and worsened by coughing, sneezing, bending, defecation, and sexual intercourse

Imaging

MRI with and without contrast is the imaging study of choice

CT scanning is useful if calcification or hemorrhage is suspected

PET scan is helpful to distinguish neoplastic lesions (with high rate of metabolism) from other lesions such as demyelination or radiation necrosis (with a much lower metabolic rate)

Treatment

Surgery Radiation Palliative chemotherapy

References

Bradley W G. Neurology in Clinical Practice. 5th edition ed. Philadelphia: Butterworth Heinemann Elsevier; 2008.

Carey WD. Cleveland Clinic: Current Clinical Medicine. 2nd edition ed. Philadelphia: Saunders Elsevier; 2010.

Ferri F F. Ferri's Clinical Advisor 2011: Instant Diagnosis and Treatment. 1st ed. Philadelphia: Elsevier; 2011.

Marx J A. Rosen's Emergency Medicine. Vol 1. 7th edition ed. Philadelphia: Mosby Elsevier; 2010.