>>
 If you or a loved one has been diagnosed with a pituitary tumor, it is important that
you have an understanding of how pituitary tumors can affect your health, and what
treatment options are available to you.
What is a pituitary tumor?
The pituitary gland is a small bean-shaped structure located at the base of the brain.
Known as the “master gland,” the pituitary controls the other endocrine (hormone
secreting) glands in the body. It secretes hormones that control sexual
development, promote bone and muscle growth, respond to stress, and fight
disease.
A tumor that grows from the pituitary gland is a pituitary tumor. The most
common type of pituitary tumor is called an adenoma. Other lesions affecting the
pituitary gland are Rathke’s cleft cysts and cranyopharyngeomas. Research shows
that tumors of the pituitary gland occur in 15 to 20% of adults. Many of these
tumors are asymptomatic. Pituitary tumors can occur in every age group, but are
more common after puberty. Like most brain tumors, the cause of pituitary tumors
is unknown. Some researchers believe they occur when a cell in the pituitary
gland becomes abnormal or mutates. The cell then reproduces additional
mutations until a tumor is formed.
Most pituitary tumors are benign (not cancerous) and are often curable.
Treatment options aim to remove the tumor or control its growth and restore
normal hormone function.
Pituitary tumors are classified as functional or non-functional.
Functional tumors (about 74% of all pituitary tumors) secrete abnormal levels of
hormones and interfere with the normal hormone regulation process. These
tumors behave according to their cell of origin and are named for the specific
hormone they produce. For example, if a tumor originates in a prolactin-producing
cell, you may develop a prolactin-secreting pituitary tumor.
Nonfunctional tumors (about 26% of all pituitary tumors) do not secrete
hormones. Instead, they grow until their size and mass effect cause headache,
vision loss, nausea, vomiting, or fatigue. Based on size, pituitary tumors can be
either microadenomas (less than 10mm) or macroadenomas (larger than 10mm).
Large tumors can press on the optic nerves and invade the cavernous sinuses,
which house the carotid arteries and the nerves involved in eye movement.
What are the symptoms of a pituitary tumor?
Symptoms of a pituitary tumor vary depending on its size and hormone secretion
function; many are asymptomatic. Some of the more common symptoms of a
pituitary tumor are tiredness, restlessness, headaches, vomiting, dizziness and
vision problems. A patient with a functional pituitary tumor may experience
symptoms related to an abnormal level of hormone secretion that will directly
relate to the specific hormones involved.
How is a diagnosis made?
If symptoms suggest a pituitary tumor, a patient’s physician will work with a team
of specialists to confirm the diagnosis. This team will include a neurosurgeon,
otolaryngologist (ear, nose and throat surgeon), endocrinologist, ophthalmologist,
pathologist and radiologist.
In addition to a thorough physical and neurological exam, several tests may be
ordered. These could include:
• Magnetic Resonance Imaging (MRI) Scan – to visualize the pituitary
gland;
• Endocrine evaluation – to measure hormone levels;
• Visual field acuity test - to detect vision loss.
What treatment options are available?
Treatment options vary depending on the type, grade, size and location of a tumor;
whether it has spread; and the age and general health of the patient. Medication,
surgery and radiation, either alone or in combination, are used to treat pituitary
tumors and return hormone levels to normal.
The goal of medication is to block the tumor from making abnormal quantities of
hormones. Some drugs used to treat pituitary tumors actually shrink the tumor,
making surgery unnecessary.
Tumors that don’t respond to medication or cause visual impairment require
surgical removal. The most widely accepted surgical approach is the transsphenoidal
(through the nose) approach. This surgery is minimally invasive,
without any visible incisions. In some cases where only part of a tumor can be
removed because of its proximity to critical areas, radiation and chemotherapy
may be used on the remaining tumor cells.
Sometimes the best treatment is observation. Small, slow-growing tumors that
have few symptoms may be observed with MRI scans until their growth or
symptoms necessitate surgery. Observation is many times the best option for
older patients with other health conditions. A patient and their doctor can weigh
the risk of symptoms developing versus the risk of treatment intervention.
|
