BRAIN TUMOR. What is it? Brain neoplasms are a diverse group of primary (nonmetastatic) tumors...
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Transcript of BRAIN TUMOR. What is it? Brain neoplasms are a diverse group of primary (nonmetastatic) tumors...
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.