Pituitary Tumors Overview: The pituitary gland is the "master gland". It is located at the base of the brain, just above the paranasal sinuses. This gland is critical for regulation of all the other glands in the body. The pituitary gland tells the other glands (adrenal glands, ovaries, testes, thyroid gland, etc.) how much hormone to make. Pituitary tumors are quite common. They occur in nearly one out of every five people. Treatment is indicated for pituitary tumors that are "functional" (i.e. cause hormonal imbalance), those that compress the optic nerves (which leads to visual field loss- decreasing the amount of the world seen by each eye), and those that are large (typically over 10mm). Some of these tumors can be treated with medicine. Others require surgery. In some cases, radiation treatment is needed as well. These tumors, called "pituitary adenomas," are almost always benign. Symptoms: The symptoms vary greatly. Vision loss or hormonal abnormalities are the most common problems. Symptoms related to hormonal abnormalities may be due to too much hormone or too little hormone. All hormones can be affected. These include: prolactin, cortisol (steroid hormones), growth hormone, thyroid hormone, testosterone, estrogen, leutenizing hormone, follicle stimulating hormone. Causes: There are no known causes of these tumors. Risk Factors: None are common. However, these tumors can be associated with multiple endocrine neoplasia syndromes (MEN I and MEN II). These syndromes are associated with tumors of multiple glands in the body. Diagnosis: At the University of Washington, we have a multi-disciplinary team that is involved in all aspects of diagnosis and patient care. This team, which includes endocrinologists (physicians specializing in hormones), radiologists, radiation oncologists, ophthalmologists, pathologists, otolaryngologists, and neurosurgeons, meets on a regular basis to discuss cases. Complications: The symptoms, and potentially serious problems caused by these tumors, may be related to the tumor "pushing" on nearby brain structures (such as the optic nerves), or from hormonal problems (either too much or too little hormone production). Treatment: The first step is to undergo an evaluation of hormone status. This starts with analysis of the patient's blood, but may require specialized blood and urine tests ordered by the endocrinologists. There are a number of different hormonal problems that can be caused by pituitary tumors. In general, these are caused by oversecretion of a hormone due to the tumor (a functional or secretory tumor), or undersecretion (hypopituitarism) of one or more hormones due to injury of the normal pituitary gland. Below are some of the hormonal syndromes that can be caused by these tumors. Endocrinology Syndromes: Cushing's Disease -- When a pituitary tumor secretes adrenocorticotropic hormone (ACTH), this causes the adrenal glands to make too much steroid hormone. This is called Cushing's disease. Tumors elsewhere in the body can also secrete ACTH, so special blood and urine tests are needed to determine the site of ACTH over production. The adrenal glands (where the steroid hormones are produced) can also be overactive. In order to differentiate this from Cushing's disease, these same blood and urine tests are needed. Symptoms of Cushing's disease include: weight gain, high blood pressure, diabetes, easy bruising, abdominal striae (red stretch marks), anxiety and depression. There is no good medical treatment for this problem. Therefore, surgery (discussed below) and/or radiation therapy (discussed below) are used. Acromegaly -- This is a syndrome caused by too much growth hormone secretion in adults. Symptoms include: enlargement of jaw, hands and feet, coarse skin, sleep apnea, high blood pressure, peripheral nerve problems. This is diagnosed with blood tests. There is no adequate medical therapy for these tumors. Therefore, surgery (discussed below), and/or radiation therapy (discussed below) are used. Prolactin over-secretion -- This is a syndrome, diagnosed by blood testing, that may be caused by tumor secretion (usually with prolactin levels greater than 200) or by pressure on the pituitary gland (usually with prolactin levels less than 100). Symptoms in women include cessation of menstrual periods, breast discharge, tiredness, loss of libido (sexual interest). Men show loss of libido and tiredness. When the tumor secretes prolactin, medical therapy is the best treatment, with success in most cases. When the tumor pushes on the normal gland, causing the gland to make too much prolactin, this is usually treated best by surgery and/or radiation. Hypopituitarism -- This is caused by tumor compression of the normal gland, such that it does not secrete enough hormones. When this happens, treating the tumor will not normalize the hormones, so hormone replacements are given. MRI is used to image the pituitary gland. Sometimes, this may be helpful as an additional study. Visual field testing is performed in the Ophthalmology department. This is a simple test. The patient looks at lights to test the size of the area of vision that each eye sees. Pituitary tumors come in all shapes and sizes. Figure on left shows a microadenoma (less than 10mm in diameter). Figure on right shows a macroadenoma (over 10mm) with a small amount of blood (hemorrhage) in the tumor. Surgery: Surgery for pituitary tumors can be done in three ways: though the nose, through an incision made under the upper lip, or through the skull (a craniotomy). The surgical approach depends on the size and location of the tumor. The two neurosurgeons who perform surgery for pituitary tumors at the University of Washington Medical Center are Dr. Daniel Silbergeld and Dr. Robert Rostomily. Endoscopic surgery (neuro-endoscopy) -- With this type of surgery, an endoscope (a tubular instrument with a built-in video camera) is inserted in the nose. Using the paranasal sinuses (natural air pockets in the skull) as a pathway, the Otolaryngology team navigates the endoscope into the sinus beneath the pituitary gland called the sphenoid sinus. The neurosurgeon then removes the thin bone beneath the gland, then opens the coverings of the gland. Curettes are then used to remove the tumor. When finished, gauze packing is placed in the nose and the patient is transferred to the recovery room. Sub-labial surgery -- Sub-labial (beneath the lip) surgery is similar to endoscopic surgery, except that an incision is made under the upper lip to gain access to the sinuses. This incision permits a wider opening than using the patient's nostrils. This wider opening may be helpful in some cases. The resection of the tumor by the neurosurgeon is aided by the operating microscope. The neurosurgeon removes the bone beneath the gland, opens the coverings of the gland, and then uses curettes to remove the tumor (see figure below). When finished, gauze packing is placed in the nose and the patient is transferred to the recovery room. A. Xray showing the sphenoid sinus (arrow 1) and the sella turcica (arrow 2), which is the part of the skull base that encases the pituitary gland. B. A rongeur (instrument for removing bone) is being used to remove the bony floor of the sella turcica. C. The covering of the pituitary gland (at the arrow) has been exposed (called the dura mater). D. After opening the covering of the pituitary gland, small curettes are used to remove the tumor. Craniotomy -- When a piece of the skull is removed to gain access to the pituitary tumor beneath the brain, this is termed a craniotomy. This approach is not needed as often as the other two described above. When the tumor grows to the sides of the normal pituitary position, this approach is helpful to access more of the tumor safely. An incision is made just behind the hairline, a piece of skull is removed (this is re-placed at the end of the operation), and the coverings of the brain (the dura) are opened. The brain is gently moved (retracted) to gain access to the pituitary tumor. Following tumor removal, the skull piece is re-placed and secured with titanium plates and screws. The patient is then transferred to the recovery room. The risks of surgery differ depending on the approach used, the type and size of the tumor, the tumor location and the patient's general health. Risks include bleeding, infection, anesthesia, injury to the normal pituitary gland (necessitating hormone replacement), spinal fluid leak (requiring placement of a spinal fluid drain during surgery when the patient is still under anesthesia), injury to the pituitary stalk (the connection between the gland and the brain) which can cause a temporary or permanent problem with a hormone (vasopressin) that controls the amount of urine made (called "diabetes insipidus"). This last problem is fairly common, and is the main determinant of the length of stay in the hospital after surgery. Radiation therapy -- Dr. Jason Rockhill is the University of Washington Medical Center expert for radiotherapy (radiation treatments) for pituitary tumors. When tumors cannot be treated adequately with medications or surgery, radiotherapy is often used. The type of radiation needed depends on the size and location of the tumor. Gamma Knife radiosurgery uses the MRI for precise treatment planning of pituitary tumor radiation. It can be used in some cases to deliver a single dose of radiation very accurately. This avoids multiple radiation treaments and does not deliver as much radiation to nearby areas of the brain as other forms of radiotherapy do. The linear accelerator (LINAC) at the University of Washington is also used for radiosurgery, especially when 8-12 doses are needed, rather than just one. This is called "fractionated stereotactic radiosurgery" (FSRT). Conformal radiation -- When tumors are large, or near the optic nerves, standard radiation (fractionated external beam radiotherapy) is administered over three to six weeks. Effectiveness of Surgery: The prognosis for pituitary tumors depends on the size and anatomical location of the tumor. For many pituitary tumors, surgery is curative. For others, it is part of a multi-step treatment program. Following pituitary surgery, patients with hormone-secreting tumors (“functional tumors”) are followed by their endocrinologist. Serum hormone levels are obtained to determine whether or not a surgical cure (a “chemical” cure) has been achieved. If a cure has not been achieved, radiation therapy may be indicated. Patients with non-functional tumors are evaluated with an MRI scan six weeks after surgery to determine whether or not there is residual tumor. Residual tumor may require radiation therapy. Risks of not having Surgery: Pituitary tumors can grow. This growth can lead to worsened symptoms and can make a tumor incurable by surgery. Hormone-secreting tumors cause oversecretion of a hormone. This is detrimental to the patient’s health and may even shorten the patient’s life. Urgency: Surgery for pituitary tumors may be urgent or elective (can be planned when it is convenient). This depends on the symptoms and tumor size. Managing Risk: Although rare, all surgical and postoperative problems are taken very seriously. Every step is taken to minimize the risks of surgery. When problems do occur, a team approach is usually used to provide optimal care. For instance, infections are managed with the University of Washington's Infectious Diseases service. The Rehabilitation Medicine service becomes involved whenever appropriate, providing speech therapy, physical therapy, occupational therapy and other services that help patients improve the quality of their lives.