Almost all pituitary tumors are benign. They can range in size from 3mm up to several centimeters in diameter. Some pituitary tumors will secrete hormones into the blood stream, and others will block all hormone production, causing low hormone levels/deficiency syndromes. Large pituitary tumors can compress adjacent neural structures, causing neurologic disorders such as vision problems.
Excess hormone production from a pituitary tumor cause conditions such as Cushing’s disease (excessive steroid production) or acromegaly (excessive growth hormone production). Prolactin-secreting pituitary tumors can cause galactorrhea (abnormal milk discharge from the breasts) and amenorrhea (irregular or absent menstrual periods) in women. Hormone deficiency from pituitary tumors can cause symptoms such as diminished energy, diminished libido and fluid or electrolyte imbalances.
Pituitary tumors may grow large enough to compress neurologic structures causing vision loss, blurry vision or double vision.
The diagnosis of pituitary tumor can be confirmed by a combination of the presenting symptoms, physical findings, results of blood testing for hormone levels (showing excess or deficiency) and imaging studies such as MRI scan or CT scan of the brain.
Treatment options for pituitary tumors consists of conservative monitoring of the tumor with serial imaging, hormonal therapy, surgical resection, and radiation. Tumors that are not large in size, not hormone producing, or in patients who cannot tolerate more aggressive treatment modalities (elderly), may oftentimes be monitored with serial imaging to make sure there is no changes in tumor size.
Some pituitary tumors can be treated medically by hormone manipulation. Parlodel or Dostinex can be used to block Prolactin-secreting tumors and shrink the tumor. Octreotide can be used to suppress excess growth hormones in patients with acromegaly due to pituitary tumor. Hormone replacement is required in patients who are deficient of pituitary hormones such as cortisol, growth hormone, thyroid and sex hormones (testosterone, estrogen or progesterone).
Tumors not sensitive to medication may be treated by surgery or radiation. The most common surgical procedure for pituitary tumor is called “transsphenoidal approach to remove pituitary tumor.” This is a micro-surgical or endoscopic approach through the nose to reach the pituitary gland. The goal of the procedure is to remove the tumor while preserving the remaining pituitary gland and maintaining normal pituitary gland hormone secretion. The average hospital stay is two or three days to recover from the surgery.
Since 2004, a less traumatic endonasal (or endoscopic) approach has been developed. This technique causes less postoperative pain and swelling. This usually shortens the hospital stay by one day.
Occasionally, a patient may require a craniotomy for resection of their tumor. The need for a craniotomy is determined by size of the lesion, and the patient’s neurologic and hormonal status, In general, the transphenoidal approach is the more common approach as it is less invasive and well tolerated. No matter the approach, the goal of surgery is to resect as much of the tumor as safely possible.
Radiation treatment options include the Gamma Knife, which uses a focused radiation beam to treat small tumor remnants, or conventional external radiation therapy for large tumor remnants, particularly if the skull base is invaded. Radiation therapy has a higher incidence of hormone deficiency after treatment.
Tumors less than 1 cm in diameter typically result in a surgical cure rate of approximately 80%. Larger and more invasive tumors have a cure rate in the 50% to 70% range and may require additional postoperative treatment with external beam radiation therapy, Gamma Knife radiation or medications.
Complications of pituitary tumor treatment include hormone deficiency, cerebrospinal fluid leakage (which may require surgical re-exploration), hematoma in the tumor bed and recurrence of the tumor (typically years after the surgery).
Dallas Neurosurgical & Spine neurosurgeons have extensive experience in the surgical and Gamma Knife treatments of pituitary tumors. DNS patients travel for treatment from the Southwest United States and Mexico.