Most common cause
The most common problem with the pituitary gland occurs when a benign tumour (used to describe a ‘growth’) also called an adenoma, develops.
Pituitary tumours are not 'brain tumours'. The term benign is used by doctors to describe a swelling which is not cancerous.
Other causes of pituitary disorders
Pituitary dysfunction in traumatic brain injury
Traumatic brain injury accounts for approximately 10% of patients attending the accident and emergency department and occurs in about 200-450 people per 100,000 of the population. Head injuries vary in severity and can have a number of consequences beyond the initial accident. These involve problems with cognition, seizures, gastrointestinal, cardiovascular, and musculoskeletal problems and also neuroendocrine dysfunction. ‘Neuroendocrine’ means problems with the endocrine (or hormone) system that originate from the brain possibly the pituitary gland or hypothalamus.
Neuroendocrine problems are mainly due to pituitary dysfunction. These can be due to alteration in the acute phase (first few hours and days), with temporary changes in blood hormone levels. These early changes usually correct with time and post injury medical management. There is also evidence that long-term neuroendocrine dysfunction resulting from permanent damage at pituitary or hypothalamic level can occur during a traumatic brain injury.
A number of trials worldwide have looked at this issue and there is no clear consensus in the medical literature how common pituitary or hypothalamic dysfunction occurs, in patients following traumatic brain injury. It is observed, that it is more common in severe traumatic brain injury.
As traumatic brain injury is common, but pituitary dysfunction following this is a rare but serious consequence, we would advise that you contact your GP if you have any concerns and experience some of the following symptoms:
- mild headaches, feeling sick, problems concentrating, poor memory, irritability, tiredness, problems sleeping, lack of appetite, sexual and fertility difficulties, depression, an increased thirst and excessive urinating.
Your GP may consider referral to an Endocrinologist if appropriate. For information and support for Traumatic Brian Injury visit www.headway.org.uk
If the blood supply to the pituitary is restricted, the gland tissue can die resulting in hypopituitarism. Infarctions can occur as a result of impaired blood flow to the pituitary gland or head trauma.
Sheehan’s Syndrome is also known as postpartum hypopituitarism, or postpartum pituitary insufficiency that may occur in a woman who has severe uterine haemorrhage during childbirth. The resulting severe blood loss causes tissue death in her pituitary gland and leads to hypopituitarism following the birth. If a woman’s pituitary gland is starved of blood due to her bleeding severely during childbirth, the gland may lose its ability to function properly. Conditions that increase the risk of an obstetric haemorrhage include multiple pregnancies (twins or triplets) and abnormalities of the placenta. Blood tests would establish hormone levels and a scan to rule out other abnormalities of the pituitary such as a tumour.
This type of tumour or cystic mass is quite rare and congenital (from birth). It exerts pressure on the hypothalamus which lies just above the pituitary gland and is responsible for releasing hormones that start and stop the release of pituitary hormones. Faster growing craniopharyngiomas affect children whilst slower growing ones affect adults. This type of tumour can cause headaches and vision problems and can affect hunger, thirst and sleep patterns. Onset of puberty and growth hormone production in children can also be affected.
Rathkes Cleft Cyst
The Rathkes pouch eventually forms the pituitary gland and normally closes early in foetal development. A remnant may persist as a cleft that lies within the pituitary gland and occasionally this remnant gives rise to a fluid-filled large cyst called Rathkes Cleft Cyst (RCC). This condition is more usually seen in adults but can occur at any age. Arachnoid Cysts and Cystic Pituitary Adenomas are other rare cyst-like tumours.
Empty Sella Syndrome (ESS) is a disorder that involves the ‘sella turcica’ a bony structure at the base of the brain that surrounds and protects the pituitary gland. ESS would show up on an MRI scan revealing a sella turcica that appears to be empty. There are two types of ESS: primary and secondary.
Primary ESS happens when a small anatomical defect above the pituitary gland increases pressure in the sella turcica and causes the gland to flatten out. The pituitary gland may be smaller than usual. Primary ESS can be associated with obesity and high blood pressure in women. The function of the pituitary gland is usually normal and may be an incidental finding when a brain MRI scan is done for other reasons.
Secondary ESS is the result of the pituitary gland regressing within the cavity after an injury, surgery or radiation therapy. Individuals with secondary ESS may have symptoms that are due to the loss of pituitary functions, for example loss of periods, infertility, fatigue and intolerance to stress and infection.
In children, ESS can be associated with early onset of puberty, growth hormone deficiency and pituitary tumours. MRI scans are useful in evaluating ESS and differentiating it from other disorders that produce an enlarged sella.
Multiple Endocrine Neoplasia (MEN)
MEN syndromes are inherited disorders (passed down in families). The disorder causes more than one gland in the body’s Endocrine system to develop growths. The affected glands may then produce abnormally increased amounts of hormones which in turn cause a variety of different symptoms.
Diagnosis is made when a patient has two or more growths common to MEN, or a patient has only one growth, but there is a family history of MEN. There is a patient group dedicated to providing support to those affected by MEN, for further information please see the AMEND website.
Another cause of hypopituitarism that may be associated with pregnancy is Lymphocytic Hypophysitis. This is due to inflammation in the pituitary caused by immune cells. The reasons why this occurs is not understood. With modern obstetric practice the occurrence of hypopituitarism after childbirth, though uncommon, is more frequently due to this condition than Sheehan’s Syndrome.