What is a pituitary macroadenoma?
A macroadenoma is a usually benign tumor composed of glandular tissue growth larger than 10 mm (those under 10 mm are called microadenomas) in the pituitary gland. The term macro simply refers to its size.
Macroadenomas can cause symptoms because they grow and press on nearby brain structures. They also can cause symptoms because they secrete excess hormones that harm the body.
Pituitary Macroadenoma Symptoms
Pituitary macroadenomas can cause symptoms by making hormones, such as in Cushing’s syndrome, acromegaly, and hyperprolactinemia. They can also cause symptoms by pressing on normal brain structures. Symptoms of a pituitary macroadenoma can include the following:
- Problems with eyesight
- Unexplained hair growth or loss
- Weight changes
- Menstrual or breast changes
- Erectile dysfunction
Pituitary Macroadenoma Treatments
Surgery is the best form of treatment 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 uses the sphenoid sinus. This natural openings in your body can be used by surgeons to make the surgery less invasive. This bone is located behind your nose, mostly within your skull.
Using precise surgical instruments, your surgeon will enter your nasal cavity and create an opening in your sphenoid bone. At Barrow, our surgeons do not make any external incisions on your face, and you will not have any bruising. Once your surgeon gains access to your sphenoid sinus (the air-filled area behind the sphenoid bone), further openings 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 high magnification to help distinguish normal pituitary tissue from the tumor.
After the tumor has been removed, your surgeon will clean the tumor cavity and seal it off. At Barrow, our surgeons specialize in endoscopic transsphenoidal pituitary surgery. Endoscopic pituitary surgery uses a tiny camera to enter the nostrils to remove the tumor.
The surgery aims to minimize trauma to the tissue surrounding your pituitary gland while facilitating a speedy recovery with as little pain or discomfort as is possible.
Most patients are able to return home the day after their surgery.
Gamma Knife radiosurgery is a highly advanced form of accurate radiation that is used to achieve similar results to the traditional surgical techniques described above. However, with Gamma Knife it can take several years for abnormal hormone levels caused by your macroadenoma to return to normal, 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.
If your pituitary macroadenoma is affecting hormone levels in your body, your doctor may prescribe medication to replace the hormones with synthetic hormones or to block the action of the macroadenoma on pituitary hormone production.
How common are pituitary macroadenomas?
A family history of multiple endocrine neoplasia type 1 (a hereditary condition) can increase your chances of developing a pituitary macroadenoma or other types of macroadenomas of the endocrine system.
How are pituitary macroadenomas diagnosed?
Your doctor may suspect you have a macroadenoma if you have the symptoms listed above. Possible tests to confirm this diagnosis include the following:
- Blood tests
- Urine tests
- Visual field tests
- Computed tomography (CT)
- Magnetic resonance imaging (MRI)
- Inferior petrosal sinus sampling (IPSS)
Is a pituitary macroadenoma curable?
A macroadenoma can be cured in many cases with surgery. When a pituitary tumor is large and has grown into nearby structures, it becomes more difficult to remove completely.
Is a macroadenoma cancerous?
A macroadenoma is almost always noncancerous, meaning it does not spread to other parts of the body.
What causes a pituitary macroadenoma?
It is not known exactly what causes a pituitary macroadenoma. Some people inherit gene mutations that increase their risk of developing these tumors. Other cases are sporadic, meaning there is no family history. Gene mutations may still be involved in sporadic cases.