For a patient with a pituitary adenoma, it is important to reduce the pressure being placed on nearby structures (generally the optic nerves and chiasm) and to restore normal hormone production.
Many pituitary adenomas must be treated surgically, although some may be treated with medication. Occasionally, a small tumor may be discovered as an unexpected finding on a MRI scan performed for some other reason. The size of the tumor, symptoms and hormone status all enter into the decision process. If the patient's vision is not threatened and hormone production is normal then observation of the tumor over time with continued MRI scans and visual field studies may be an option.
Most surgery for removal of pituitary adenomas is performed via a "transphenoidal approach," which means, simply, that we enter through the nose. The pituitary gland is located under the brain and sits in a small saddle-shaped area of the skull called the "sella." The sella forms one of the walls of the sphenoid sinus, which is connected to the nose. In some cases, the neurosurgeon will be assisted by an ENT surgeon. This approach is very direct and does not leave any visible scars on the patient. An incision, when necessary, is usually performed under the lip or nostril. A surgical microscope or "endoscope" with a mini-camera is used to allow us to see an image on a monitor to guide the surgeons through the area.
Surgery is sometimes performed via a transcranial approach (through the skull) for removal of a pituitary adenoma. This larger operation is reserved for tumors not appropriate for a transphenoidal approach due to their large size or growth pattern.
Recovery from this type of surgery is usually quick, and most patients are discharged from the hospital in two to three days. A risk from pituitary surgery is "diabetes insipidus," a condition where the kidney produces large volumes of urine. The complication if it occurs is usually temporary. It can be easily controlled with medication administered by a nose spray. Leakage of spinal fluid through the nose is another possible complication. If it occurs it is usually corrected with a patch of fat to seal the leak.
Radiation therapy is recommended for patients with known residual tumors following surgery. At the time of diagnosis, some very large tumors may have already invaded other parts of the brain. Surgery would be performed to decompress the optic nerves and chiasm (release the pressure being placed on them by the tumor). Radiation therapy may be used to minimize the risks of tumor regrowth.
There is also another type of surgery called "stereotactic radiosurgery," a technique whereby a precise dose of radiation is delivered directly to a tumor. It uses a reduced dose of radiation given over five to 10 days, and has been used to treat both residual and recurring tumors. In some cases, it might also be used for newly diagnosed tumors. Stereotactic radiosurgery can be performed either after surgical removal or as a primary therapy.