OTHER PRIMARY BRAIN TUMORS
Chordoma is a rare type of cancer that occurs in the bones of the skull and spine. Chordomas are usually slow growing, and it is rare for the tumor to have metastasized (spread to other areas of the body) at the time the tumor is initially diagnosed; however, metastasis can occur when the tumor is more advanced.
Some of the early symptoms may be very nonspecific and include any of the following:
- Neck pain
- Double vision
- Hearing changes
Imaging studies, such as a computed tomography (CT) scan, and/or magnetic resonance imaging (MRI) are useful in diagnosing this type of cancer, and are used in developing a treatment plan.
As with many different brain tumors, surgical removal of the tumor is often the chosen treatment. This may be very challenging due to the proximity of the tumor to the brain and spinal cord. The doctors have experience with many different types of neurosurgery, including minimally invasive options. Click here for more information about the surgical treatment options available at Houston Methodist.
Tumors in the pineal gland region are rare, constituting less than one percent of all primary brain tumors. Most tumors occur in children, so the incidence in adults is very low. Metastasis is found in about 10 percent to 20 percent of the cases, usually late in the disease.
The location of the pineal gland and other tumors in this region often causes a buildup of cerebrospinal fluid in one of the fluid-filled ventricles of the brain. This condition is referred to as hydrocephalus or hydrocephaly (also referred to as “water on the brain”). This can lead to symptoms such as headache, nausea, vomiting and neurological symptoms.
Tumors that arise from the cells of the pineal gland are characterized based on their potential for rapid growth and metastasis (spread to other regions of the body).
- Pineocytomas are slow-growing tumors with a low potential to spread.
- Pineoblastomas are more aggressive, with a high potential to metastasize, although the spread is usually limited to the cerebrospinal fluid (CSF).
- Tumors containing both cell types also occur.
Diagnosing Pineal-Region Tumors:
Diagnostic imaging, such as magnetic resonance imaging (MRI), is used in the diagnosis of pineal gland tumors and developing a treatment plan. Analysis of the cerebrospinal fluid may be used to distinguish the particular type of cancer involved, and a biopsy may also be used to determine the tumor type.
Treating Pineal-Region Tumors:
Treatment of the tumor may involve surgery, radiation, chemotherapy or a combination of any of all of these. Surgery to correct the hydrocephalus is also necessary. Tumors of the pineal gland (pineoblastomas), are very similar to embryonal tumors. Although they are not embryonal tumors, the treatment of pineoblastomas is often similar.
CENTRAL NERVOUS SYSTEM EMBRYONAL TUMORS
Central nervous system (CNS) embryonal tumors are thought to derive from fetal cells that remain in the CNS after birth. These tumors are usually malignant (they can spread from the original site). There are two types of CNS embryonal tumors:;
- Medulloblastomas form in the cerebellum — the area of the brain that controls movement, balance, and posture.
- CNS primitive neuroectodermal tumors form in the cerebrum — the area of the brain that controls thought processes and reasoning.
Meduloblastomas account for less than two percent of all primary brain tumors, and the preponderance of cases occur in children, where they account for 18 percent of brain cancers.
Diagnosing CNS Embryonal Tumors:
Magnetic Resonance Imaging (MRI) is often used in the diagnosis of CNS embryonal tumors. Because these tumors often spread to the spinal cord, an MRI of the spine may be performed in addition to the MRI of the brain. For the same reason, doctors may want to collect a sample of the cerebrospinal fluid by lumbar puncture (also referred to as a spinal tap) a procedure in which a needle is inserted between the spinal vertebrae into the spinal cord.
Treating CNS Embryonal Tumors:
Surgery to remove as much of the tumor as possible is the first approach to treating CNS embryonal tumors. Challenges to complete removal of the tumor include the size of the tumor, extensive blood supply, and the likelihood that the tumor has already metastasized (spread) at the time of the initial surgery. In addition to removing the tumor, surgeons may need to perform procedures to correct hydrocephalus (also referred to as hydrocephaly, or water on the brain) caused by excess cerebrospinal fluid. In many cases radiation therapy and/or chemotherapy will be recommended after surgery, although radiation may not be appropriate for young children.
Because CNS embryonal tumors are extremely rare in adults, you want to be treated by a team with experience in treating rare cancers, such as the specialists at Houston Methodist.
GERMINOMAS, TERATOMS & NONGERMINOMAS - GERM CELL TUMORS
Symptoms usually reflect the location of the tumors in the head and brain.
- Tumors within the skull, or cranium
- Pineal region – The pineal gland is located deep within the brain. Tumors located in the pineal region are often associated with headaches and vision problems.
- Above the sella turcica – The pituitary gland is located deep in the brain, above a structure called the sella turcica. This location is referred to as the “suprasellar” region. Germ cell tumors in this location may press against the pituitary gland and cause hormone-related symptoms.
- Within the mouth – A particular kind of germ cell tumor, a teratoma, is often located here.
Diagnostic procedures usually will include imaging studies such as magnetic resonance imaging (MRI). Because germ cell tumors tend to spread through the cerebrospinal fluid (CSF), doctors may also want to get a sample of that fluid by performing a lumbar puncture (also referred to as a spinal tap) in which a needle is inserted between the spinal vertebrae into the spinal cord to withdraw a sample of fluid. Imaging studies and the analysis of your CSF will help your doctors to develop a treatment plan and to monitor your response to treatment.
Blood tests can also be useful in diagnosing germ cell tumors. Your doctors may want to look for tumor markers in your blood or CSF or check the levels of hormones that may be altered if a tumor is pressing on a gland within your brain. The following tests may be used to investigate suspected germ cell tumors in your brain:
- Tumor markers are molecules that are present on the surface of tumor cells, but absent or present in smaller amounts on normal cells. These molecules can be released into the blood or CSF so that their levels will be elevated when a tumor is present. Alpha-fetoprotein is a tumor marker for germ cell tumors.
- Hormones are normal substances, but tumors may be an abnormal source. Beta-human chorionic gonadotropin is prodiced in excess by some but not all germ cell tumors.
There are several different types of germ cell tumors, and treatment varies according to the type of tumor. Most patients with germ cell cancer will need to be treated with combination chemotherapy for at least 3 cycles.
- Germinomas may be treated with radiation and/or chemotherapy.
- Teratomas may be treated first with surgery, followed by radiation or chemotherapy.
- Nongerminomas may be treated first with chemotherapy followed by radiation therapy. Another option is to use very high doses of chemotherapy to destroy cancer cells. This treatment also destroys the stem cells that produce blood cells. To overcome this, the patient’s stem cells are harvested before chemotherapy and infused after the chemotherapy.