Prolactin (HPL) secreting tumors or prolactinomas Lactation Irregular periods Amenorrhea Infertility Impotence Osteoporosis
Growth Hormone (HGH) secreting tumors (acromegaly) Gigantism  Enlargement of facial features,   hands and feet Heart disease, hypertension arthritis Carpel tunnel syndrome Amenorrhea, impotence, lactation
Adrenal gland stimulating hormone (ACTH) (Cushing's Disease)          Widened face with acne and flushing  Fatty deposits over back of neck  Stretch marks, easy bruising, hair growth  Ddiabetes mellitus  Muscle loss and fatigue  Depression and psychosis
Nelson's Syndrome (ACTH)   Following adrenalectomy for treatment of Cushing's disease   Increased melanin pigmentation of the skin
Thyroid gland stimulating hormone (TSH)    Heat intolerance  Fine tremor  Weight loss

Some tumors may secrete more than one hormone, such as growth hormone and prolactin. There are very rare tumors which secrete leutinizing hormone (LH) and follicle stimulating hormone (FSH).

There are many other tumors which occur within the sell tursica or in the adjacent cavernous sinus which may mimic pituitary tumors: 

Diagnosis . . .

The clinical diagnosis depends upon the combination of symptoms and signs resulting from the size of the tumor and/or the type of hormone produced.

Pituitary adenomas may be imaged with CT or MR scans. 
MR imaging is the most sensitive technique, allowing identification of tumors a fraction of an inch in size.

Evaluation of pituitary function is possible by measuring hormone levels in the blood and urine. Sometimes provocative tests are necessary to judge pituitary function. Examples include measuring the level of growth hormone hours after ingesting glucose by mouth or measuring serum ACTH and cortisol levels after taking a steroid medication by mouth. 

Occasionally the measurement of ACTH levels in the venous blood draining the pituitary (in the petrosal sinus) gives the surgeon a clue as which side of the gland very small ACTH secreting tumors reside. 

Formal evaluation of the visual fields are useful in outlining  peripheral visual loss before and after surgery .

Treatment . . .

Medical Therapy:

Medical therapy is useful in treating some hormone secreting adenomas:

Prolactinomas: dopamine agonists which effect the D2 receptors for dopamine effectively treat prolactin tumors. About 80 to 90% of patients will normalize their serum prolactin levels. Nearly 80% of tumor will become smaller. Parlodel (bromocriptine) has been used for many years. A new drug, Dostinex (carbergoline), many be more effective with fewer side effects. It can be given by mouth twice a week. 

Cushing's disease: medical treatment for tumors which cause the over secretion of corticosteroids by the adrenal glands is unsatisfactory because of their side effects and response rates. Two classes of medication are used: those which interfere with the production of steroids in the adrenal glands and those which act within the brain. Removal of the adrenal glands is an option when pituitary surgery and medical measures fail to control Cushing's disease. This may lead to rapid growth of the pituitary tumor and massive blood levels of ACTH. ACTH stimulates melanin production in the skin, darkening the skin color. This is termed Nelson's syndrome

Acromegaly: There are three types of medications which effect the production or utilization of growth hormone. Most patients treated with dopamine agonists, such as Parlodil (bromocriptine) achieve reduction in HGH levels, but few reach normal levels. Somatostatin analogs are a second class of medications useful in the treatment of acromegaly. Somatostatin analogs which are administered by injection every few weeks are available. Most patients develop low levels of growth hormone, but very few develop levels which are considered a cure of the disease. A third class of drugs have just become available. This drug (Somavert-pegvisomant) blocks peripheral HGH receptor and can normalized HGH levels in more than 90% of patients.

Surgery: 

The history of pituitary surgery goes back about 100 years. Harvey Cushing was one of the pioneers and his monograph, The Pituitary Body and Its Disorders, was a significant contribution to our field. Cushing helped develop both the transphenoidal approach and transcranial operations for pituitary tumors.

Nowadays pituitary surgeons utilize the transsphenoidal approach for most pituitary tumors. This avoids many of the complications of transcranial surgery. It is safe , effective and requires a short stay in the hospital. Surgery has the advantage of rapidly lowering hormone levels. The surgeon exposes the sellar tursica through an incision inside the nose or under the upper lip.  

 

Side view showing tumor compressing optic nerves	Postoperative view showing decompression of optic nerves

The tumor is identified, separated from the pituitary gland and removed. For small tumors (less than 10 mm in diameter) the cure rate is greater than 50% . Pre-operative pituitary function is preserved in many or most patients. Abnormally high hormone levels are lowered or normalized. Some tumors, especially tumors larger than 1 cm.  tumors can recur and may require additional treatment. Infection, cerebrospinal leak, vascular injury, double vision, visual loss, pituitary deficiency are rare sequels of this commonly performed procedure. 

Radiation Therapy:

 Fractionated radiotherapy is effective in controlling the growth of nonsecretiong pituitary adenomas. Generally doses of 45 Gy are given in 1.8 Gy fractions with the expectation that the treatment will control the growth of 70% to 90% of tumors with a 1% chance of optic neuropathy and visual loss. Additionally about 1/2 of patients treated will developed hypopituitarism and require hormonal treatment. It seems that individuals who have surgery in addition to radiation therapy have a greater chance of control of disease progression after radiation therapy.

Although XRT controls the growth of most secreting tumors, it is less effective in normalizing hormone levels. Less than 1/2 of patients with secreting tumors will achieve normal levels after many years.

Radiosurgery: 

Gamma Knife radiosurgery has become increasingly more important in the control of pituitary adenomas. This technique allows for focused, high dose treatment of pituitary adenomas and results in greater rate  of control of tumor growth and better rates of normalization of increased hormone secretion. It has been used as the primary treatment  of small pituitary tumors in individuals who do not require decompression of the optic nerves. There should be a few millimeters of separation of the tumor surface from the optic nerves to allow effective tumor doses and safe doses delivered to the optic nerves. 

Probably 90% of patients treated with Gamma Knife radiosurgery with achieve control of tumor growth and more than 1/2 of patients will normalize hormone levels over months to years. 

Follow-up:

Patients are seen within a few days of surgery to remove nasal packing. Post operative evaluation of pituitary function is carried out weeks to months after surgery. Pituitary dysfunction may occur years after radiation or radiosurgery so long term evaluation of pituitary hormones is necessary. Interval measurement of visual fields, and imaging of the pituitary may be carried out as well.  

Reference . . .

The Pituitary Network Association:  http://www.pituitary.org/