What is ectopic posterior pituitary?

Ectopic posterior pituitary is a condition in which the back end (posterior) of the pituitary gland is in an abnormal position.

The pituitary gland is a pea-sized organ located in the center of the brain, connected to the hypothalamus. It produces and regulates the release of hormones that control growth, sexual development and function, metabolism and the body’s response to stress.

In normal anatomy, the posterior (rear) lobe of the pituitary is connected to the hypothalamus by the pituitary stalk and the anterior (front) lobe is attached to the posterior lobe. In ectopic posterior pituitary, the connection between the pituitary and the hypothalamus may be abnormal (e.g., pituitary stalk interruption syndrome). The anterior pituitary lobe may also be underdeveloped or missing.

Ectopic posterior pituitary is associated with the under-production of growth hormone and in some cases with the under-production of all pituitary hormones (panhypopituitarism). It can be associated with other pituitary conditions, including septo-optic dysplasia and Kallmann syndrome.

Causes of ectopic posterior pituitary

Ectopic posterior pituitary occurs as a result of abnormal pituitary gland development in the growing fetus. In many cases, a cause cannot be found. In a growing number of cases, genetic mutations related to ectopic posterior pituitary can be identified.

Signs and symptoms of ectopic posterior pituitary

The primary symptom of ectopic posterior pituitary is abnormal slow-down of growth or short stature, caused by the under-production of growth hormone.

When the condition causes other hormones to be under-produced or missing, additional symptoms in infants, children or adolescents may include:

• Low blood sugar (hypoglycemia)
• Prolonged jaundice at birth
• Poor appetite
• Weight loss or weight gain
• Sensitivity to cold
• Delayed puberty
• Small penis in males

These symptoms may resemble other conditions or medical problems. Always consult your doctor for a diagnosis.

Testing and diagnosis of ectopic posterior pituitary

Your doctor will usually begin with a physical exam and with questions about any symptoms you may have noticed.

• Height and weight will be charted to look for changes in or abnormal growth patterns.
• Abnormalities in pubertal development will be assessed.
• History of potentially related conditions (e.g., low blood sugar) will be reviewed.

If signs indicate the possibility of ectopic posterior pituitary, additional tests to diagnose the condition and understand the cause may include:

• Neurological exam to check mental status, coordination, reflexes and muscle function
• Eye test to check for loss of vision, including narrowing field of vision
• Blood and urine tests to check hormone levels; the blood tests, or venous sampling, involve taking blood from peripheral veins in the arms that will look at hormone levels originating from the pituitary gland in the brain
• Magnetic resonance imaging (MRI) or computerized tomography (CT) scan to get visual images of the pituitary gland, brain and spinal cord

Treatment for ectopic posterior pituitary

Ectopic posterior pituitary treatment focuses on restoring normal levels of hormones in the body should they be reduced. Hormone replacement therapy substitutes medically administered hormones for those normally produced by the pituitary gland.

Outlook

For most children and adolescents with an ectopic posterior pituitary gland and reduced pituitary hormone production who are identified promptly, hormone replacement therapy is effective in restoring normal hormone levels and promoting typical growth and puberty.

Follow-up care

When medication is needed to supplement hormone production, periodic follow-up tests are needed to ensure that the treatment continues to work effectively. Dosage levels and the combination of medications may need to be adjusted over time.

Why choose CHOP?

Children with ectopic posterior pituitary often require care from many pediatric specialties.

The Neuroendocrine Center at Children’s Hospital of Philadelphia (CHOP) offers families a coordinated and multidisciplinary approach to treatment for neuroendocrine disorders. Our team combines the expertise of pediatric endocrinologists, neuro-oncologists, neuro-surgeons, neuro-ophthalmologists, neuro-radiologists, geneticists and pathologists.

All our team members have vast experience in the treatment of complex neuroendocrine conditions like ectopic posterior pituitary.