Pituitary Disorders -- A Short Overview
By William H. Ludlam, M.D., Ph.D.
Director, OHSU Pituitary Unit
Last Updated: 6/20/2003
Pituitary diseases are relatively uncommon in the general population but if misdiagnosed or untreated can lead to serious complications including blindness and, ultimately, death. Yet, due to their infrequency as well as to symptomatic diversity, an initial diagnosis is frequently elusive and the subsequent management of pituitary disease can be complex.
The pituitary gland is located in front of the hypothalamus and below the optic chiasm. The "anterior lobe" of the pituitary makes six hormones: Prolactin, ACTH, thyroid stimulating hormone (TSH), LH, FSH and growth hormone (GH) and the "posterior lobe" of the pituitary releases vasopressin (ADH) and oxytocin. The maintenance of appropriate levels of these hormones constitutes a major control mechanism for virtually all physiologic activities.
Pituitary disease is most often caused by non-cancerous tumors, which are classified as either functioning (overproducing one or more hormones) or non-functioning. Clinically significant lesions are thought to occur with an incidence of about 35 cases per million per year but some data suggests that the incidence may be much higher. Other causes of pituitary disorders include infiltrative, immunologic, vascular, hypothalamic, infectious and metastatic disease as well as trauma.
In addition to the relatively low frequency of pituitary disorders, patients suffering with pituitary diseases can initially present with diverse symptoms to virtually any medical specialty (Table 1). This combination renders the initial diagnosis daunting plus creates a situation in which most physicians (including many endocrinologists and neurosurgeons) do not have the requisite experiential base to comfortably manage patients with pituitary disease. Hence, the vast majority of physicians seek to develop an ability to recognize or suspect patients with pituitary diseases and refer them to a specialty group for conclusive diagnosis, treatment and management.
Physicians often miss pituitary disease because its symptoms are similar to those of many other diseases. To assist in this, a partial list of common signs and symptoms of pituitary hormone deficiency and excess are listed in Table 2. Within the context of the indicated symptoms, the following three questions can also help the clinician identify a potential pituitary disease.
First, are there signs or symptoms of deficiencies in pituitary hormones? Hormonal deficiencies can occur in isolation or in combinations.
Second, are there signs or symptoms of excess in pituitary hormones? Hormonal overproduction can also occur in isolation or in combinations and can occur in the background of other hormonal deficiencies.
Third, are there signs or symptoms of a space-occupying pituitary lesion? Clinical manifestations include headaches, visual problems (especially peripheral vision loss) and occasionally seizures or cranial nerve deficits.
While a preliminary diagnosis of pituitary disease can be challenging, the initial basic work-up for pituitary disease is straightforward and can be easily initiated if pituitary disease is suspected, as described in Table 3. A head MRI should be performed if either the laboratory evaluation indicates the presence of pituitary disease or if a space-occupying lesion is suspected.
If the work-up indicates the presence of a pituitary tumor or disease, many clinicians will seek the help of pituitary disease experts to help treat and manage the patient. Treatment typically includes a combination of medicines and surgery and may involve irradiation. However, the majority of non-prolactin secreting tumors require surgery. Pituitary disease patients should be evaluated pre- and post-operatively by an endocrinologist comfortable in managing neuroendocrine diseases.
The most common surgical approach for the resection of pituitary tumors is transsphenoidal, or through the sphenoid sinus which is an air space between the nose and the pituitary. The sphenoid sinus can be surgically accessed by going under the lip or by going through the nose. Surgical outcome studies have repeatedly shown that surgeons highly experienced in this procedure obtain the highest cure rates with the lowest rates of recurrence, post-operative complications and pituitary dysfunction.
Table 1: Examples of Medical Specialties To Which Pituitary Disease Patients May Present (partial list)
- Obstetrics and Gynecology -
breast discharge , menstrual irregularities, infertility, facial hair growth
- Urology -
impotence, decreased sexual interest
- Neurology -
headache, muscle weakness,
carpal tunnel syndrome
- Ophthalmology -
blurred vision, visual field loss, double vision
- Dermatology -
dry, oily, sweaty skin
- Orthopedics -
joint pain, joint/bone abnormalities
- Family Practice/Internal medicine
all of the above, frequent urination, fatigue, depression
Table 2: Partial List of Signs and Symptoms of
Pituitary Hormone Disregulation
- Pituitary Hormone Deficiency
- ACTH (Adrenal Insufficiency):
abdominal discomfort (N/V), joint aches, dizziness with standing
- TSH (Hypothyroidism) :
constipation, weight gain, cold intolerance, muscle weakness, fatigue, dry skin, hair loss, memory loss
- LH/FSH (Hypogonadism) :
sexual dysfunction, hot flashes, menstrual irreg., male breast
- GH (Adult Growth Hormone Deficiency):
lack of vigor, decreased exercise tolerance, weight gain around the belly, memory problems
- ADH (Diabetes insipidus):
Excessive thirst and urination
- Pituitary Hormone Excess
- Prolactin (Hyperprolactinemia):
breast discharge, sexual dysfunction
- ACTH (Cushing's Disease):
moon face, weight gain around belly, purple stretch marks, red face, acne, hirsutism, HTN, DM, muscle weakness, easy bruising, recurrent infections
- GH (Acromegaly):
enlarged hands/feet/jaw, gaps between teeth, carpal tunnel
syndrome, oily skin, joint pain, diabetes mellitus
Table 3: The Basic Pituitary Disease/Pituitary Tumor Work-up
Hormones to check
- 8:00 am serum cortisol
(or cortrosyn stimulation test)
- TSH and Free T4
- LH and FSH
- Testosterone (men)
- IGF-1 (Insulin-like Growth Factor-1)
- 24 hour Urine Free Cortisol (for Cushing's)
Imaging (if indicated):
Head MRI (with and without gadolinium)