Brain / Spinal Tumors

Introduction:

Primary brain tumors are tumors that arise from cells originating in the tissue of the brain and skull.  Primary brain tumors rarely spread to other areas of the body, but they can spread to other parts of the brain and to the spinal.  Prognoses of primary brain tumors are determined by histologic type (cell type), grade of malignancy, and extent of the tumor and by the patient’s age, the performance status, and the duration of symptoms. Some primary brain tumors are curable by surgery alone, and some are curable by surgery, chemotherapy. and radiation therapy.   The postoperative size is often the most important factor in the prognosis equation.  Dr. Maroon and his associates are experts in the delicate surgery required to remove complex brain tumors, and allow for the greatest chance of survival.

Surgery:

Surgical removal of brain tumors is generally recommended for most types of brain tumors. The location and size determines both the pre-operative and post-operative symptoms associated with the tumor and the resection. Surgery should be as complete as possible but neurologic function should be preserved. Diagnosis by Stereotaxic biopsy can be used for lesions that are difficult to reach and resect.

 

Other Treatments:

Radiation therapy has a major role in the treatment of most tumor types and can increase the cure rate or prolong disease-free survival. Chemotherapy may prolong survival in some tumor types. Gliadel wafers (TM) are sometimes used to apply chemotherapy directly to the resected tumor bed.

Other treatments include radiosensitizers, hyperthermia, or interstitial brachytherapy used in conjunction with external-beam radiation therapy.

Types of Tumors:

Metastases to the brain from a primary tumor that is outside the central nervous system (CNS) are more common than primary tumors of the brain. The most common primary tumors that metastasize to the brain are lung, breast, melanoma, leukemia, lymphoma, and kidney.

Cord Tumors

Tumors of the spinal cord, like tumors of the brain are both benign and malignant in nature and their growth similar to brain tumors will cause symptoms and signs in the level at which the nerve tissue is compressed.  This picture shows a intramedullary tumor or tumor within the cord itself.  Cord tumors can also be extramedullary or outside the cord but within the neural canal. Tumors such as schwannoma or nerve sheath tumors will grow along the openings of the neural canal where the nerve roots exits.  Surgery for all tumors involving the spinal cord are difficult due to the potential injury to the nerves and possible resulting nerve injury or paralysis.  In some cases of malignant tumors a needle biopsy can be done and radiation or other treatments can be started.  Tumors of the spine can often press on to the spinal cord and require surgical decompression.  This type surgery will then often require spinal fusion to reconstruct the spine.

(Click Here to Learn More About Spinal Cord Tumors)
——————————————————————————–

Cellular Classification
Histological classification for adult brain tumors is as follows:1

Glial tumors: Gliomas constitute the most common primary central nervous system (CNS) tumors. Of the gliomas, astrocytomas of variable malignancy are the most prevalent. Cerebral astrocytomas are subdivided into categories (grades) based on the degree of tumor anaplasia and the presence or absence of necrosis.

I.  astrocytic tumors

• noninfiltrating – These astrocytomas are relatively slow-growing tumors such as juvenile pilocytic and subependymal astrocytomas, which occur most frequently in children but can occur in adults.
  • juvenile pilocytic
    subependymal
• infiltrating – These tumors are more infiltrative than the juvenile pilocytic and subependymal astrocytomas but are still relatively slow-growing tumors.
  • well-differentiated mildly and moderately anaplastic astrocytoma
  • anaplastic astrocytoma – These tumors are highly anaplastic with obvious vascular abnormalities. This grade III astrocytoma grows more rapidly than the more differentiated astrocytomas.
  • glioblastoma multiforme – This grade IV astrocytoma is a poorly differentiated, rapidly growing tumor that occurs most often in adults.
• ependymal tumors – Ependymal tumors are considered to arise from ependymal cells that line the ventricles and from ependymal rests. They vary in grade of malignancy.
  • myxopapillary and well-differentiated ependymoma – These tumors include myxopapillary ependymoma and well-differentiated ependymoma, and are often curable.
  • anaplastic ependymoma – These tumors have more features of anaplasia and appear mitotically more active than the myxopapillary or well-differentiated ependymomas. Although previously considered to do worse than the well-differentiated ependymoma, conflicting evidence suggests that patients treated with surgery and radiation therapy might do nearly as well.
  • ependymoblastoma – These are generally tumors of childhood and are considered by some to be primitive neuroectodermal tumors. They are rare.
• oligodendroglial tumors – Oligodendroglial tumors are gliomas that arise from the oligodendroglia. They vary in grade of malignancy, and prognosis is related to grade.
  • well-differentiated oligodendroglioma – These tumors are usually slow-growing and well circumscribed.
  • anaplastic oligodendroglioma – These tumors are comparable to the highly anaplastic gliomas in prognosis.
• mixed tumors – Mixed gliomas can occur with combinations of generally 2, but sometimes 3, different cell types: astrocytoma, ependymoma, and/or oligodendroglioma. Survival statistics are inexact for this group because the cell types and grade of the most malignant-appearing cells influence prognosis. In general, these tumors carry a prognosis that is between the prognoses of well-differentiated and anaplastic astrocytomas.
  • mixed astrocytoma-ependymoma
  • mixed astrocytoma-oligodendroglioma
  • mixed astrocytoma-ependymoma- oligodendroglioma
• medulloblastoma – Medulloblastoma is a rapidly growing tumor arising in the posterior fossa and is found almost exclusively in children and young adults. It has the tendency to spread from the brain to the spinal axis. Prognosis is dependent on the staging following surgical resection.

II. Nonglial tumors:

• pineal parenchymal tumors – Pineal parenchymal tumors vary in histology and grade of malignancy relative to patient age at occurrence. They can vary from the slow-growing pineocytoma to the more malignant and faster growing pineoblastoma. Astrocytomas can also grow in this location (see above), as can a variety of primary germ cell tumors: germinoma, embryonal carcinoma, choriocarcinoma, and teratoma. These uncommon tumors vary in prognosis. The absence of biopsy specimens in many series make the prognosis for each tumor type difficult to evaluate.
  • pineocytoma
  • pineoblastoma
  • astrocytoma (see above)
• germ cell tumors
  • germinoma
  • embryonal carcinoma
  • choriocarcinoma
  • teratoma
• craniopharyngioma – Craniopharyngioma is a tumor that arises from the remains of a structure found in the developing embryo in the region of the pituitary gland. This tumor causes symptoms and signs by pressing on vital areas of the brain and the optic nerves; it also causes internal hydrocephalus by obstructing the foramen of Monro in children.
• meningiomas – Meningiomas arise from the meninges surrounding the brain and spinal cord and are generally slow-growing. There are other variants that constitute a group called malignant meningioma and include malignant meningioma, hemangiopericytoma, papillary meningioma, and meningeal sarcoma. Malignant meningiomas are more likely than other meningiomas to metastasize within the craniospinal axis.
  • meningioma – Meningioma is usually curable with surgery if the initial resection is complete. The shape of the tumor is a prognostic factor and should be considered in planning surgery. Incomplete resection associated with lobulated and mushrooming patterns of tumor growth is associated with a higher risk of recurrence.2
  • malignant meningiomas – The prognosis for patients with malignant meningioma is worse than for patients with the more well-differentiated meningiomas.
  • anaplastic meningioma
  • hemangiopericytoma
  • papillary meningioma
• choroid plexus tumors – Choroid plexus tumors are rare tumors arising from choroid plexus epithelial cells. The more benign form is choroid plexus papilloma; the more malignant form is called anaplastic choroid plexus papilloma. These latter tumors are most likely to spread within the craniospinal axis.
  • choroid plexus papilloma
  • anaplastic choroid plexus papilloma

Images

Disclaimer

References:

Kleihues P, Burger PC, Scheithauer BW, et al.: Histological typing of tumours of the central nervous system. Berlin: Springer-Verlag, 2nd ed., 1993.

Nakasu S, Nakasu Y, Nakajima M, et al.: Preoperative identification of meningiomas that are highly likely to recur. Journal of Neurosurgery 90(3): 455-462, 1999.

If you have specific questions that are not addressed in these materials, please call your neurosurgeon 412.647.3604.
Call, toll-free, at 888-234-4357 to learn more.