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COMMON BRAIN TUMORS IN ADULTS |
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CNS Tumors in Adults at the Time of Diagnosis
● Metastatic tumors 30%
● Primary CNS tumors 70%
Gliomas 65%
(2/3’s of primary brain tumors are gliomas, and 2/3’s are malignant)
Meningiomas 15%
Schwannoma 6%
Primitive neuroectodermal tumors 6%
Pituitary tumors 5%
Craniopharyngiomas 3%
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Metastatic Tumors |
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● One quarter of all patients with systemic cancer develop CNS metastatic disease.
● Single lesion (50%), multiple lesions (50%), or carcinomatous meningitis.
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Most common cause is lung carcinoma
● Other common causes
are colon, renal,
breast and melanoma (65% of melanomas metastasize to the
brain, often hemorrhagic)
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Gliomas |
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● Most common primary tumor in adults, two-thirds of which are malignant.
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Significant prognostic indicators:
Patient age
Tumor location and resectability
Neurologic function at diagnosis
Average survival with maximal therapy has remained about 1 year. Tumors recur
locally and infiltrate extensively.
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Meningiomas |
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● Tumors occur along the skull base, the falx and tentorium, and over the
convexity
● Although the pathology is usually benign, the tumors can invade from
the dura into the bone, and entrap cranial nerves and vessels
● Meningiomas have
a varied course. Some are quiescent for many years without treatment, some are
cured by surgical resection, and others recur extensively despite surgery and
radiation.
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Schwannomas
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● Nerve sheath tumors frequently occur on the vestibular nerve (acoustic neuroma), but can occur on other cranial nerves.
● Small tumors can be treated
with observation, surgery, or stereotactic radiosurgery, and larger tumors
require surgery.
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Pituitary Tumors
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● Tumors are classified by size (microadenoma <1cm, macroadenoma >1cm), and by
hormone secretion
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Macroadenomas present with symptoms of pituitary dysfunction
or visual symptoms
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Microadenomas
typically present with endocrine symptoms
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Prolactinomas are the most common tumor. Other hormone secreting
tumors include growth-hormone, ACTH, and mixed tumors
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Pituitary apoplexy
(hemorrhage into a pituitary tumor) can cause sudden visual loss and hypopituitarism that can be life-threatening.
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