Anterior pituitary disorders

The anterior (front) lobe of the pituitary gland releases a variety of hormones that affect growth, physical and sexual development, and other endocrine glands. Oversecretion or undersecretion of certain hormones by the anterior lobe of the pituitary gland will cause other endocrine glands to over- or under-produce certain hormones.

Disorders caused by over-production of anterior pituitary hormones:

Disorders caused by over-production of hormones by the pituitary gland are fortunately extremely rare in childhood and adolescence. They can result from overactive cells within the anterior pituitary that don't respond or shut off to the normal signals within the body. If parts of the pituitary gland enlarge enough due to growth of these overactive cells, the child may experience headaches and vision changes like double vision or a loss of peripheral vision.

Too much growth hormone results in acromegaly and gigantism, a condition of very rapid growth, a coarsening of facial features, enlargement of hands and feet, and sometimes high blood sugars. Too much prolactin can cause a delay in puberty, a disruption of normal periods in females, and a milky discharge from the nipples. Too much ACTH secretion can result in a rare condition known as Cushing's disease, caused by high levels of the stress hormone, cortisol. Cushing's disease causes very pronounced weight gain with a marked slowing of height gain, high blood pressure, high blood sugars, weakness, and irritability.

These conditions are frequently diagnosed by specific blood and/or urine tests. Frequently, the diagnosis is then confirmed with imaging of the pituitary gland by MRI (magnetic resonance imaging or MRI). The treatment may be medical by taking medicine to slow the pituitary gland down or may be more involved with surgical or radiation treatment. The diagnosis and treatment of these conditions can be very complicated and must be managed by an experienced pediatric endocrinologist who can properly interpret lab and imaging results.

Disorders caused by under-secretion of anterior pituitary hormones:

Disorders caused by under-secretion of anterior pituitary hormones are also very rare in pediatrics but can have serious consequences. They may be caused by an isolated injury to a portion of the anterior pituitary or a failure of part of the gland to develop normally. Anterior hormone deficiencies may include one or more hormones.

1. Growth hormone deficiency: in growing children, growth hormone deficiency results in short stature and/or very slow growth rates. In older children, the symptoms of growth hormone deficiency are harder to define but include low muscle mass, weaker bones, and lower energy levels.
2. ACTH deficiency: this is also called central adrenal insufficiency as the adrenal glands do not make enough of the stress hormone cortisol. This condition can be life-threatening if not recognized and treated properly. Cortisol is critical on a daily basis but especially when we are sick and stressed. ACTH deficiency can result in low blood pressure, weakness, dehydration, abdominal pain, weight loss, and difficulty in recovering from illnesses or surgeries.
3. Gonadotropin deficiency: FSH (follicular stimulating hormone) and LH (luteinizing hormone) are responsible for initiating and maintaining puberty. These hormones stimulate the testes to make testosterone in boys and the ovaries to make estrogen in girls. Deficiencies in FSH and LH can result in a failure of puberty to start or a disruption in normal pubertal progression.
4. TSH deficiency: hypothyroidism (low thyroid hormone levels) results when there is not enough TSH made to stimulate the thyroid gland to produce thyroid hormone. Hypothyroidism can result in fatigue, constipation, dry skin, brittle hair, poor growth, feeling cold all the time, and disruptions to normal periods in girls.

Diagnosis of anterior pituitary deficiencies:

The diagnosis of anterior pituitary deficiencies starts with a detailed history of your child's symptoms, a thorough review of their growth charts, and a physical examination by an experienced pediatric endocrinologist. The endocrinologist will frequently check to see if there are any puberty changes if the child is at an age where this would normally be expected. Based on any concerning findings, we will then typically obtain blood and/or urine tests and possibly an x-ray of your child's left hand to see how their growth plates are maturing in relation to their actual age. This initial evaluation may lead to more detailed testing such as a growth hormone or ACTH stimulation test.

Growth hormone and ACTH stimulation tests are performed over a few hours during a scheduled visit to our Infusion Center. Your child will have an IV placed and be given 1-2 medications that should stimulate growth hormone or cortisol production by the body (depending on what we are worried about). We then draw blood from the IV to see if the levels of growth hormone or cortisol increase as we would expect. These tests are interpreted by pediatric endocrinologists and are the best tests we currently have to make a diagnosis of growth hormone or ACTH deficiency.

Treatment of anterior pituitary deficiencies:

Fortunately, we have medical treatment for all anterior pituitary deficiencies. This includes giving the hormone(s) that your child is not making enough of. Treatment must be constantly adjusted based on your child's weight, growth, and clinical response. This does include frequent visits to our clinic, usually every 4-6 months. We judge the clinical response by growth, puberty changes, and also get blood work occasionally to make sure our doses are appropriate and safe.

Growth hormone is given through a daily injection under the skin. It cannot be given orally with a pill. ACTH deficiency is treated with oral steroids (hydrocortisone or prednisone) two to three times daily with clear instructions on giving higher doses during times of illness, surgery, or severe stress. Deficiencies in FSH and/or LH are treated by giving the relevant sex hormone, either testosterone or estrogen. These medications are given in much lower doses than an adult would receive and we adjust the dose over time to mimic what would normally happen in a child progressing through puberty. This allows for the best growth and development of secondary sexual characteristics. TSH deficiency is treated with thyroid hormone replacement (levothyroxine), a pill given once daily.

Close collaboration with a pediatric endocrinologist allows for very good management of any anterior pituitary deficiency. Our goal is to as closely mimic what the body would otherwise be doing and to thus allow for normal growth and development.

What is hypopituitarism?

Hypopituitarism, also called an underactive pituitary gland, is a condition that affects the anterior (front) lobe of the pituitary gland - usually resulting in a partial or complete loss of functioning of that lobe. The resulting symptoms depend on which hormones are no longer being produced by the gland.

In some cases, the production of all of the pituitary hormones decreases or stops, usually due to damage to the entire pituitary gland. This condition is called panhypopituitarism. Learn more.