Surgery for Pituitary Tumors
The main treatment for many pituitary tumors is surgery. How well the surgery works depends on the type of tumor, its exact location, its size, and whether it has spread into nearby structures.
Transsphenoidal surgery: This is the most common way to remove pituitary tumors. Transsphenoidal means that the surgery is done through the sphenoid sinus, a hollow space in the skull behind the nasal passages and below the brain. The back wall of the sinus covers the pituitary gland.
For this approach, the neurosurgeon makes a small incision along the nasal septum (the cartilage between the 2 sides of the nose) or under the upper lip (above the upper teeth). To reach the pituitary, the surgeon opens the boney walls of the sphenoid sinus with small surgical chisels, drills, or other instruments depending on the thickness of the bone and sinus. A newer approach is to use an endoscope, a thin fiber-optic tube with a tiny camera lens at the tip. In this approach, the incision under the upper lip or the front part of the nasal septum is not needed, because the endoscope allows the surgeon to see well through a small incision that is made in the back of the nasal septum. The surgeon passes instruments through normal nasal passages and opens the sphenoid sinus to reach the pituitary gland and remove the tumor. The use of this technique is limited by the tumor’s position and the shape of the sphenoid sinus.
The transsphenoidal approach has many advantages. First, no part of the brain is touched during the surgery, so the chance of damage to the brain is very low. There is also no visible scar. But it’s hard to remove large tumors this way. When the surgery is done by an experienced neurosurgeon and the tumor is a microadenoma, the cure rates are high (greater than 80%). If the tumor is large or has grown into the nearby structures (such as nerves, brain tissue, or the tissues covering the brain) the chances for a cure are lower and the chance of damaging nearby brain tissue, nerves, and blood vessels is higher.
Craniotomy: For larger or more complicated pituitary tumors, a craniotomy may be needed. In this approach the surgeon operates through an opening in the front and side of the skull. The surgeon has to work carefully beneath and between the lobes of the brain to reach the tumor. Although the craniotomy has a higher chance of brain injury than transsphenoidal surgery for small lesions, it’s actually safer for large and complex lesions because the surgeon is better able to see and reach the tumor and nearby nerves and blood vessels.
For both transsphenoidal surgery and craniotomies, the doctor may use image-guidance with MRI or CT scans before surgery to help plan the best surgical approach. Some centers also use intraoperative MRI (where MRI scans are done in the operating room one or more times during the surgery), but many doctors still consider this to be experimental.
As a general rule, smaller pituitary tumors are easier to treat with surgery. The larger and more invasive the tumor, the less likely the tumor can be cured by surgery.
Possible side effects of surgery
Surgery on the pituitary gland is a serious operation, and surgeons are very careful to try to limit any problems either during or after surgery. Complications during or after surgery such as bleeding, infections, or reactions to anesthesia are rare, but they can happen. Most people who have transsphenoidal surgery will have a sinus headache and congestion for up to a week or 2 after surgery.
If surgery causes damage to large arteries, to nearby brain tissue, or to nerves near the pituitary, in rare cases it can result in brain damage, a stroke, or blindness.
When doctors use the transsphenoidal approach to operate on the pituitary gland, they create a temporary pathway between the nasal sinuses and airways and the brain. Until this heals, a person can get meningitis, which is infection and inflammation of the meninges (the thin protective layers covering the brain). Damage to the meninges can also lead to leakage of cerebrospinal fluid (the fluid that bathes and cushions the brain) out of the nose.
Diabetes insipidus (discussed in Signs and Symptoms of Pituitary Tumors) may occur right after surgery, but it usually improves on its own within 1 to 2 weeks after surgery. If it is permanent, it can be treated with a desmopressin nasal spray.
Damage to the rest of the pituitary can lead to other symptoms from a lack of pituitary hormones. This is rare after surgery for small tumors, but it may be unavoidable when treating some larger macroadenomas. If pituitary hormone levels are low after surgery, this can be treated with medicine to replace certain hormones normally made by the pituitary and other glands.
For more general information about surgery as a treatment for tumors, see Cancer Surgery.
Last Medical Review: May 8, 2014 Last Revised: December 17, 2014