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Primary Intracranial Tumors
Gliomas are the most common intracranial neoplasm, accounting for half of all primary intracranial neoplasms.
The remainder consist of meningiomas, pituitary adenomas, neurofibromas.
Tumor Clinical Features Treatment and Prognosis
Glioblastoma Presents commonly with nonspecific Course is rapidly progressive.
multiforme complaints and increased intracranial pressure. poor prognosis.
As it grows, focal deficits develop. is usually not possible, and response
to radiation therapy is poor.
Astrocytoma Presentation similar to glioblastoma multiforme Prognosis is variable. By the time of
but course more protracted, often over several diagnosis, total excision is usually
years. Cerebellar astrocytoma, especially in impossible; tumor often is not
children, may have a more benign course. radiosensitive. In cerebellar
astrocytoma, total surgical removal is often possible.
Medulloblastoma Seen most frequently in children. Generally Treatment consists of surgery combined
arises from roof of fourth ventricle and leads to with radiation therapy and
increased intracranial pressure accompanied by chemotherapy.
brain stem and cerebellar signs. May seed subarachnoid space.
Ependymoma Glioma arising from the ependyma of a ventricle, Tumor is not radiosensitive and is best
especially the fourth ventricle; leads early to treated surgically if possible.
signs of increased intracranial pressure. Arises also from central canal of cord.
Oligodendroglioma Slow-growing. Usually arises in cerebral Treatment is surgical and usually
hemisphere in adults. Calcification may be successful.
Brain stem glioma Presents during childhood with cranial nerve. Tumor is inoperable; treatment is by
palsies and then with long-tract signs in the irradiation and shunt for increased
limbs. Signs of increased intracranial pressure intracranial pressure occur late.
Cerebellar Presents with disequilibrium, ataxia of trunk Treatment is surgical.
Sometimes familial. May be associated with retinal and spinal vascular
lesions, polycythemia, and hypernephromas.
Pineal tumor Presents with increased intracranial pressure, Ventricular decompression by shunting
sometimes associated with impaired upward is followed by surgical approach to
gaze (Parinaud=s syndrome) and other deficits tumor; irradiation is indicated if tumor is
indicative of midbrain lesion. malignant. Prognosis depends on
histopathologic findings and extent of tumor.
Craniopharyngioma Originates from remnants of Rathke=s pouch Treatment is surgical, but total removal
above the sella, depressing the optic chiasm. may not be possible.
May present at any age but usually in childhood, with endocrine dysfunction and bitemporal field defects.
Acoustic neurinoma Ipsilateral hearing loss is most common initial Treatment is excision by
symptom. Subsequent symptoms may include translabyrinthine surgery, craniectomy,
tinnitus, headache, vertigo, facial weakness or or a combined approach. Outcome is
numbness, and long-tract signs. (May be familial usually good.
and bilateral when related to neurofibromatosis.) Most sensitive screening tests are MRI and
brain stem auditory evoked potential.
Meningioma Originates from the dura mater or arachnoid; Treatment is surgical. Tumor may recur
compresses rather than invades adjacent neural if removal is incomplete.
structures. Increasingly common with advancing age. Tumor size varies greatly. Symptoms vary
with tumor siteCeg, unilateral exophthalmos (sphenoidal ridge); anosmia and optic nerve
compression (olfactory groove). Tumor is usually benign and readily detected by CT scanning
Primary cerebral Associated with AIDS and other Treatment is by whole-brain
lymphoma immunodeficient states. Presentation may be irradiation; chemotherapy may have an
with focal deficits or with disturbances of adjunctive role. Prognosis depends
cognition and consciousness. May be upon CD4 count at diagnosis.
indistinguishable from cerebral toxoplasmosis.
Clinical Findings
A. Symptoms and Signs: Intracranial tumors may lead to a generalized disturbance of
Treatment
Treatment depends on the type and site of the tumor (Table 24B3) and the condition of the patient. Complete surgical removal may be possible if the tumor is extra-axial (eg, meningioma, acoustic neuroma) or is not in a critical or inaccessible region of the brain (eg, cerebellar hemangioblastoma). Surgery also permits the diagnosis to be verified and may be beneficial in reducing intracranial pressure and relieving symptoms even if the neoplasm cannot be completely removed. Clinical deficits are sometimes due in part to obstructive hydrocephalus, in which case simple surgical shunting procedures.