Non Functioning Pituitary Adenomas
What are Non Functioning Pituitary Adenomas?
These non functioning pituitary adenomas do not result in excess hormone production and therefore do not lead to a clinical syndrome. However, they can cause symptoms resulting from tumor growth that creates pressure on your pituitary gland and on the structures near the pituitary.
Nonfunctioning pituitary adenomas are almost always benign.
Non Functioning Pituitary Tumor Symptoms
Not all nonfunctioning tumors cause symptoms. Those that are symptomatic typically cause the following:
- Nausea and vomiting
- Loss of appetite
- Weight loss
- Fatigue, decreased energy
- Slow or incoherent thinking
- Dizziness or spatial disorientation
- Joint pains
- Infertility and irregular or nonexistent menstruation in women
- Infertility, impotence, and loss of body and facial hair in men
- Diminished or nonexistent sex drive
- Pressure or mass effect
- Loss of vision which could involve the loss of peripheral vision or decreased acuity in one or both eyes
- Double vision
Non Functioning Pituitary Tumors Treatments
If your tumor is not large enough to cause symptoms, your doctor may prescribe a series of follow-up visits to monitor its growth. Most nonfunctioning pituitary tumors grow slowly, so surgical treatment can sometimes be delayed until symptoms occur.
Surgery is the best form of treatment if your tumor is causing symptoms and the only way to achieve a cure. Your surgeon will gain access to your pituitary gland using the transsphenoidal approach—so named because the route your surgeon takes crosses, or transects, your sphenoid bone. This bone is located behind your nose mostly within your skull.
Using precise surgical instruments, your surgeon will make an incision through your nasal cavity to create an opening in your sphenoid bone. Once your surgeon gains access to your sphenoid sinus (the air-filled area behind the sphenoid bone), further incisions will be made until a hole is created in the sella turcica—the bone that cradles and protects your pituitary gland.
Once your tumor appears in the operative field, removal of the tumor can proceed. Your surgeon will use magnification to distinguish normal pituitary tissue from the nonfunctioning pituitary tumor.
After your tumor has been removed, your surgeon will clean the tumor cavity and seal it.
At Barrow Neurological Institute at Dignity Health St. Joseph’s Hospital and Medical Center, our surgeons specialize in two types of surgery for nonfunctioning tumors:
- Microsurgery uses an operating microscope to help your surgeon distinguish between structures in and around your pituitary gland.
- Endoscopic surgery uses small tubes and a tiny camera to help your surgeon remove your tumor in small pieces.
Both surgeries aim to minimize trauma to the tissue surrounding your pituitary gland while facilitating a speedy recovery with as little pain or discomfort as possible. Each technique has its own inherent advantages and disadvantages, and your surgeons will work with you to help determine which is the best fit for you.
Most patients are able to return home the day after their surgery for removing a nonfunctioning pituitary tumor, and nasal packing is seldom required.
There is no way to mediate the growth of nonfunctioning pituitary tumors through medical therapy.
However, medicines may be prescribed to help alleviate some symptoms associated with the disease. Hormone replacement drugs can also be given if surgery to remove your tumor does not restore normal pituitary function.
Gamma Knife radiosurgery is a highly advanced form of radiotherapy that is used to achieve similar results to the traditional surgical techniques described above. However, with Gamma Knife, it can take a period of several years for your tumor to shrink and its associated symptoms to decrease, rather than days or weeks as with traditional surgery.
The “knife” in this surgery is actually made up of many small beams of radiation focused on a single point. Each individual beam is too weak to damage healthy tissue, but at the point where the beams converge they deliver a dose of radiation that is lethal to the tumor.
Gamma Knife is an outpatient procedure, does not involve any incisions, and requires only brief sedation under general anesthetic.
Typically, Gamma Knife is used as a secondary treatment for nonfunctioning pituitary tumors, with surgical removal being the first choice. However, if your tumor has recurred or if you are not healthy enough to undergo traditional surgery, Gamma Knife might be the best option.
How common are nonfunctioning pituitary tumors?
Nonfunctioning tumors account for about 30 percent of all pituitary tumors.
How are nonfunctioning pituitary tumors diagnosed?
A combination of the symptoms listed above may make your doctor suspect a nonfunctioning pituitary tumor. If your doctor suspects a nonfunctioning pituitary tumor, a combination of hormonal, imaging, and ophthalmological tests can be used to pinpoint the problem.
Because nonfunctioning pituitary adenoma tumors can disrupt the ability of your pituitary gland to make and regulate several bodily hormones, blood tests for bodily hormones can suggest the cause of disease. Some hormones that might be implicated are the following:
- Thyroid-stimulating hormone
- Adrenocorticotropic hormone
- Luteinizing hormone
- Estradiol (women)
- Testosterone (men)
- Growth hormone
- Insulin-like growth factor-1
Decreased or loss of peripheral vision can be a sign of a nonfunctioning pituitary tumor.
Magnetic resonance imaging (MRI) and computed tomography (CT) can be used to locate the tumor, assess the threat it poses to adjacent structures, and plan a surgical route if necessary.