Tumors of meninges |
Meningioma | Originates from the dura mater or arachnoid; compresses rather than invades adjacent neural structures. Increasingly common with advancing age. Tumor size varies greatly. Symptoms vary with tumor site—eg, unilateral proptosis (sphenoidal ridge); anosmia and optic nerve compression (olfactory groove). Tumor is usually benign and readily detected by CT scanning; may lead to calcification and bone erosion visible on plain radiographs of skull. | Treatment is surgical. Tumor may recur if removal is incomplete. |
Tumors of neuroepithelial origin |
Glioblastoma multiforme | Presents commonly with nonspecific complaints and increased intracranial pressure. As it grows, focal deficits develop. O6-methylguanine-DNA methyltransferase promoter methylation positivity (seen in 40% of cases) and isocitrate dehydrogenase 1/2 mutations (seen in 10% of cases) carry better prognosis. | Course is rapidly progressive, with poor prognosis (< 20% survival at 2 years). Total surgical removal is usually not possible. Radiation therapy and temozolamide may prolong survival. Tumor treatment fields added to temozolamide after completion of radiation therapy prolong survival. |
Astrocytoma | Presentation similar to glioblastoma multiforme but course more protracted, often over several years. Cerebellar astrocytoma may have a more benign course. Isocitrate dehydrogenase 1/2 mutations (seen in a majority of cases) carry better prognosis in grade II and III tumors. | Prognosis is variable. By the time of diagnosis, total excision is usually impossible; tumor may be radiosensitive and temozolamide is also helpful in grade II and III tumors. In cerebellar astrocytoma, total surgical removal is often possible. |
Ependymoma | Glioma arising from the ependyma of a ventricle, especially the fourth ventricle; leads to early signs of increased intracranial pressure. Arises also from central canal of cord. | Tumor is best treated surgically if possible. Radiation therapy may be used for residual tumor. |
Oligodendroglioma | Slow-growing. Usually arises in cerebral hemisphere in adults. Calcification may be visible on skull radiograph. Co-deletion of 1p/19q and isocitrate dehydrogenase 1/2 mutation required for diagnosis. | Treatment is surgical and usually successful. Radiation and chemotherapy (temozolamide or procarbazine, lomustine, and vincristine) are used in grade II and III tumors. |
Brainstem glioma | Presents during childhood with cranial nerve palsies and then with long tract signs in the limbs. Signs of increased intracranial pressure occur late. | Tumor is inoperable; treatment is by irradiation and shunt for increased intracranial pressure. |
Neuronal and mixed neuronal-glial tumors | Slow-growing; usually arise in cerebral hemispheres; often associated with seizures. Some are benign (eg, dysembryoblastic neuroepithelial tumors) and some have malignant potential (eg, ganglioglioma). | Resection is not always necessary for benign tumors unless seizures are medically refractory, but is indicated for those with malignant potential. |
Medulloblastoma | Seen most frequently in children. Generally arises from roof of fourth ventricle and leads to increased intracranial pressure accompanied by brainstem and cerebellar signs. May seed subarachnoid space. Wingless activated tumors carry best prognosis (> 90% 5-year survival). | Treatment consists of surgery combined with radiation therapy and chemotherapy; 5-year survival exceeds 70%. Wingless activated tumors may require less aggressive treatment. |
Pineal tumor | Presents with increased intracranial pressure, sometimes associated with impaired upward gaze (Parinaud syndrome) and other deficits indicative of midbrain lesion. | Ventricular decompression by shunting is followed by surgical approach to tumor; irradiation is indicated if tumor is malignant. Prognosis depends on histopathologic findings and extent of tumor. |
Tumors of the Sellar Region |
Pituitary adenoma | Functioning adenomas present with symptoms of hormone secretion; nonfunctioning adenomas present with symptoms of local mass effect (eg, bitemporal hemianopsia, hypopituitarism) or are found incidentally. | Prolactin-secreting adenomas are treated with bromocriptine or cabergoline. Others are surgically resected. Pituitary hormone replacement may be required. |
Craniopharyngioma | Originates from remnants of Rathke pouch above the sella, depressing the optic chiasm. May present at any age but usually in childhood, with endocrine dysfunction and bitemporal visual field defects. | Treatment is surgical, but total removal may not be possible. Radiation may be used for residual tumor. |
Germ cell tumors (germinomas and nongerminomatous germ cell tumors) | Two most common locations are pineal and suprasellar regions. The pineal region presentation is as described in pineal tumors, above. Suprasellar tumors present with hypothalamic and pituitary dysfunction such as diabetes insipidus, delayed or precocious puberty, or growth hormone deficiency. | Germinomas are treated with radiation; prognosis is good for localized tumors. Chemotherapy is added for nongerminomatous germ cell tumors. |
Tumors of Cranial and Spinal Nerves |
Acoustic neurinoma (also referred to as acoustic neuroma) | Ipsilateral hearing loss is most common initial symptom. Subsequent symptoms may include tinnitus, headache, vertigo, facial weakness or numbness, and long tract signs. (May be familial and bilateral when related to neurofibromatosis.) Most sensitive screening tests are MRI and brainstem auditory evoked potential. | Treatment is excision by translabyrinthine surgery, craniectomy, or a combined approach. Outcome is usually good. |
Lymphomas |
Primary cerebral lymphoma | Associated with AIDS and other immunodeficient states. Presentation may be with focal deficits or with disturbances of cognition and consciousness. May be indistinguishable from cerebral toxoplasmosis. | Treatment is high-dose methotrexate and corticosteroids followed by radiation therapy. Prognosis depends on CD4 count at diagnosis. |
Unclassified |
Cerebellar hemangioblastoma | Presents with dysequilibrium, ataxia of trunk or limbs, and signs of increased intracranial pressure. Sometimes familial. May be associated with retinal and spinal vascular lesions, polycythemia, and renal cell carcinoma. | Treatment is surgical. Radiation is used for residual tumor. |