Tumors in the region of the pineal gland account for about one percent of brain tumors. Many different types of tumors with completely different characteristics occur in this region, but the most common type is called a germinoma.
When pineal tumors occur in childhood, they can produce an early puberty, especially in boys. This type of tumor causes pressure in the channel that connects two cavities of the brain where fluid flows around the brain and spinal cord. The tumor can cause pressure inside the brain (leading to hydrocephalus), swelling inside the eye and vomiting. It can also cause paralysis of the upward gaze, sagging or drooping of the upper eyelid and a loss of reflex reactions in the eye.
Causes and Risk Factors
Pineal tumors can occur at any age, but they are most common in childhood.
A neurologic evaluation should be done if a patient has slowly increasing signs of mental dysfunction, new seizures, persistent headaches or evidence that there is pressure inside the skull (such as vomiting or swelling or protrusion of the blind spot at the back of the eye). A neurologist (a doctor who has received special additional training in the diagnosis and treatment of disorders of the brain, spinal cord and nerves) will perform a complete examination.
He or she may also request that a magnetic resonance imaging (MRI) scan or a computed tomography (CT or CAT) scan be done, as well as chest X-rays, to determine if the tumor has spread from another part of the body. An MRI usually finds low-grade astrocytomas earlier than CT. Cerebral angiography is rarely used to diagnose a brain tumor, but it may be done before surgery.
Depending on the patient's symptoms, specialized tests may be done, including tests of the field of vision, the sharpness of vision and hearing. If the results of other tests are not conclusive, an examination of the fluid that surrounds the brain and spinal cord may be done, although it is usually unnecessary. It is essential for diagnosing chronic or subacute meningitis or for identifying benign hypertension inside the skull.
Treatment of a brain tumor depends on the nature of the tumor, how rapidly it is growing, what symptoms it is causing and where it is located. Several treatment approaches may be used. Surgery is usually done to make a diagnosis and to improve symptoms. This may be enough to cure benign tumors.
Radiation therapy is required to treat gliomas. Radiation therapy may also be beneficial in the short-term for tumors that have spread from other parts of the body. Chemotherapy also benefits some patients with such tumors.