Pineal Tumors

Pineal region tumors represent about 1% of all brain tumors.

Pineal tumors arise in the region of the pineal gland. This gland is a small structure deep within the brain. These tumors represent about 1% of all brain tumors but account for 3% to 8% of the intracranial tumors that occur in children. At least 17 different types of tumors may occur in this region, and many are benign.

The three most common types of pineal region tumors are:

• gliomas,
• germ cell tumors, and
• pineal cell tumors.

Pineal Tumor Causes

As with most brain tumors, the cause of pineal tumors is largely unknown. Research is underway to discover the possible causes.

Pineal region tumors arise in or near the pineal gland, which is a small midline structure located deep in the midbrain area, near many vital structures. The pineal gland is located next to the aqueduct of Sylvius, which serves as a passage allowing cerebrospinal fluid (CSF) to leave the center of the brain where it is first produced. Pineal tumors often compress this aqueduct, causing a build-up of the pressure of CSF in the brain (called hydrocephalus). Expansion of the ventricles causes pressure on the adjacent tissues of the brain, all of which exist in the closed space of the skull. Blockage of the flow of this fluid can cause some of the common presenting symptoms of these tumors, which include:

• headache,
• nausea and vomiting,
• seizures,
• memory disturbances, and
• visual changes.

The intracranial pressure may even increase to life-threatening levels, demanding urgent treatment.

Hydrocephalus can be treated by placement of a ventriculoperitoneal shunt (VP shunt). The VP shunt is a long tube placed within one of the CSF-containing spaces of the brain, then passed under the skin to the abdominal cavity to provide a pathway for CSF drainage and absorption in the abdomen.

Alternatively, the hydrocephalus can be controlled by a procedure known as a stereotactic third ventriculostomy. The third ventriculostomy creates a tiny opening in the bottom of the brain using a small endoscope to allow the CSF to escape. This procedure is usually performed under local anesthesia (without the need for general anesthesia).

Pineal region tumors may also cause visual changes as a result of the involvement of the nearby tectal region which has a primary role in controlling eye movements. These changes may include:

• inability to focus on objects,
• double vision, and
• impairment of eye movements.

These problems may improve or resolve with the treatment of the tumor. Certain germ cell tumors may secrete hormones that cause endocrinologic disturbances, such as the early onset of puberty in children.

Brain tumors can be difficult to diagnose because the symptoms are similar to many other problems. Also, if a tumor grows slowly, the symptoms could develop over a long period of time. Symptoms sometimes appear as problems in other portions of the body, such as numbness in the legs or arms. Pressure from a growing tumor can cause specific symptoms such as a headache. The American Cancer Society (ACS) has reported that half of all brain tumors cause headaches; however, it is important to realize that less than 1% of headaches are the result of brain tumors. Here are some other signs and symptoms to watch out for according to ACS and National Cancer Institute (NCI):

• seizures
• nausea and vomiting
• weakness or loss of feeling in the arms and legs
• stumbling or lack of coordination in walking
• abnormal eye movements or changes or blurriness in vision
• hearing problems such as ringing or buzzing
• drowsiness
• changes in personality, behavior, or memory
• changes in speech

These symptoms could be an indication of a brain tumor or other problems such as stroke. Only a doctor can make the diagnosis. If you suffer any of these symptoms, you should seek medical help right away.

It's natural for the patient and family members to have many questions throughout the person's diagnosis and treatment. A diagnosis of a brain tumor can be overwhelming - and frightening. That's why it might help to write down questions and bring them to doctor appointments. As the doctor answers questions, take notes or have a family member accompany the patient and take notes. The more the patient and family members know and understand about each aspect of care, the better.

The patient also might find it helpful to share their feelings with others in similar situations. Check to see if local support groups for people with brain tumors and their families are available in your area. Hospitals often sponsor these groups. Doctors and nurses also may be able to make recommendations on where to find the emotional support the patient and family might need.

Below is a sampling of the types of questions to ask the physician in different stages of cancer diagnosis and treatment.

Before undergoing a biopsy:

• How long will it take? Will I be awake? Will it hurt?
• Will I need to stay in the hospital?
• How soon will I know the results?
• If I do have cancer, who will talk with me about treatment? When?

After diagnosis

• Is this cancer? If so, will you write down the medical name for it? Are there other names for this same cancer?
• What is the difference between a benign and a malignant tumor?
• What stage and grade is my cancer?
• What are the treatment choices? Which do you recommend? Why? What is your experience in treating this type of cancer?
• What are the risks and possible side effects of each treatment?
• What are the chances that the treatment will be successful?
• What new treatments are being studied in clinical trials? Would a clinical trial be appropriate?
• Will you send my records to another physician if I decide to get a second opinion?

Before treatment begins

• What is the goal of this treatment?
• When will the treatments begin? When will they end? Will I have to stay in the hospital?
• How will I feel during therapy? What are the possible side effects?
• How will you manage the side effects?
• If I have pain, how will I manage it?
• What is the treatment likely to cost?
• What can I do to take care of myself during therapy?
• What effect will cancer/cancer therapies have on my eating habits? Are there any foods I should avoid? Are there any foods I could benefit from eating?
• How will I know if the therapy is working?
• Will I be able to continue my normal activities during treatment?
• Whom should I contact if I have a question or problem, especially after office hours?

What are specific treatment options for:

• surgery
• radiation
• chemotherapy
• immunotherapy

If cancer is in remission and/or after you have completed cancer treatment

• How likely is a recurrence of cancer? (for example, will cancer come back?)
• How often will you see me and for how long?
• Will I be able to lead a "normal life?"
• What kind of ongoing health needs will I have?
• Are there long-term side effects of the treatment or disease that may occur?
• How often do they occur? When are they most likely to occur?

The signs and symptoms of a brain tumor initially may be vague and come and go, making the diagnosis of a brain tumor difficult. Other diseases can cause similar signs and symptoms.

Diagnosing a brain tumor involves several steps. The doctor may perform a neurologic exam, which among other things includes checking the patients:

• vision,
• hearing,
• balance,
• coordination and
• reflexes.

Depending on the results of the neurologic exam, the doctor may request one or more of these tests:

Computerized Tomography (CT) Scan

The CT scan uses a sophisticated X-ray machine linked to a computer to produce detailed, two-dimensional images of the brain. The patient lies still on a movable table, guided into what looks like an enormous doughnut where the images are taken. A special dye may be injected into the bloodstream after a few CT scans are taken. The dye helps make tumors more visible on X-rays. The CT scan generally takes less than 10 minutes.

Magnetic Resonance Imaging (MRI) Scan

The MRI scan uses magnetic fields and radio waves to generate images of the brain. The patient lies inside a cylindrical machine for 15 minutes to an hour. MRI scans are particularly useful in diagnosing brain tumors because they outline soft tissues of the body as well as bones. Sometimes a special dye is injected into the bloodstream during the procedure. The dye usually makes tumors easier to distinguish from healthy tissue.

Angiogram

An angiogram involves injecting a special dye into the bloodstream. The dye, which flows through the blood vessels in the brain, can be seen by X-ray. This test helps show the location of blood vessels in and around a brain tumor.

X-rays of the Head and Skull

An X-ray of the head may show alterations in skull bones that could indicate a tumor. It may show calcium deposits, which are sometimes associated with brain tumors. However, a routine X-ray is a far less sensitive test than brain scans and so is used less often.

Other Brain Scans

Other tests, such as magnetic resonance spectroscopy (MRS), single-photon emission computerized tomography (SPECT), or positron emission tomography (PET) scanning, help doctors gauge brain activity by studying brain metabolism and chemistry as well as blood flow within the brain. These scans can be combined with MRIs to help doctors understand the effects of a tumor on brain activity and function, but doctors don't typically use them to make an initial diagnosis of a brain tumor.

If the doctor sees what appears to be a brain tumor on a brain scan, especially if there are multiple tumors, he or she may test for cancer elsewhere in the patient's body before making a definitive diagnosis. Letting the doctor know of a prior history of cancer anywhere in the body, even many years earlier, is important.

The only test that can absolutely make a diagnosis of a brain tumor is a biopsy. This can be done as part of an operation to remove the tumor or can be done in a separate procedure in which only a small sample of tissue is obtained. A needle biopsy may be used for brain tumors in hard-to-reach areas within the brain. The surgeon drills a small hole, called a burr hole, into the skull. A narrow, thin needle is then inserted through the hole. Tissue is removed using the needle, which is frequently guided by CT scanning.

The tissue is then viewed under a microscope to determine if it is a tumor, and if so, what type of tumor. Additional tests on the tissue are often done to help determine the exact type of tumor, which may help in guiding treatment.

Surgery is essential to obtain a sample of tumor tissue so the pathologist can confirm a precise histological diagnosis. Precise diagnosis is required to plan appropriate therapy. Benign pineal tumors can be removed surgically. Malignant pineal tumors are treated differently depending on the type of malignant tumor (cancer) found.

• Pineocytomas are treated with surgery alone as no benefit from radiation therapy has been shown.
• The most common malignant tumor in this area is germinoma. This is very sensitive to both radiation and chemotherapy and is curable in most cases.
• Other malignant germ cell tumors occurring in this region are treated with chemotherapy followed by radiation therapy. Non-germ cell tumors may be treated with newer techniques including specially focused radiation therapy called using stereotactic techniques.

Surgery, radiation, and other cancer therapies can damage hormone-producing regions of the body. An endocrinologist specializes in such hormone disorders.

• The patient's primary healthcare will consult an endocrinologist to determine if hormone deficiencies are present.
• Most hormone problems can be well controlled with medical therapies.

In recent years the prognosis for children with pineal tumors has improved dramatically.