Introduction

What is empty sella syndrome (ESS)?

Empty sella syndrome (ESS) is a condition identified by brain imaging in which the sella turcica, a cavity that holds the pituitary gland, appears empty. This occurs when fluid from the surrounding brain area pushes into the cavity, causing the pituitary gland to become flattened. As a result, brain scans are unable to visualise the gland, thereby giving the impression of an empty sella turcica.

Pituitary gland and tumours

The pituitary gland is known as the “master gland” because it controls most of the body’s hormones.¹ It rests in a small bony space at the base of the skull, called the sella turcica.² Pituitary tumours are common and do not spread like cancer. They can press against the gland and nearby structures, interfering with hormone levels and vision.² To treat these, doctors typically perform surgery or propose radiotherapy.² Unfortunately, while these methods are usually effective, they can also alter the shape and affect the function of the pituitary gland, potentially inducing secondary ESS.

Causes and development of ESS

Primary ESS

Scientists have identified multiple causes for primary ESS. In some cases, it is caused by a weakness in a thin tissue layer known as the diaphragma sellae, which usually sits over the pituitary gland.³ When this layer is weak, brain fluid can press down into the sella turcica, flattening the pituitary.³ Another contributing factor may be increased fluid pressure in the skull, which is associated with obesity or high blood pressure.

Secondary ESS

This can be due to:

• Pituitary tumour surgery: May remove some tissue or alter the shape of the gland
• Radiotherapy: Damages pituitary cells over time, causing the gland to shrink or become scarred⁴
• Other conditions: A tumour pressing on the gland, bleeding into the pituitary gland, or certain chronic illnesses may also cause ESS

How does it develop?

In both forms, fluid collects in the sella turcica and presses on the pituitary gland. Over time, this can cause the gland to produce fewer hormones, or in some cases, lead to symptoms such as headaches or vision problems.

Clinical manifestations

Many people with ESS have no symptoms at all. In fact, they often discover the condition incidentally when undergoing a brain scan for other issues such as headaches or eye problems. However, in some cases, ESS can lead to notable symptoms.

Hormonal (endocrine) symptoms

• Low hormone levels: Can lead to persistent fatigue, weight changes, or irregular menstrual cycles
• Elevated prolactin levels: The hormone responsible for breast milk production may also cause infertility or difficulties with sexual health
• Growth hormone deficiency: Can reduce energy levels, muscle mass, and bone strength⁵

Neurological symptoms

• Headaches (the most common complaint)
• Dizziness
• Rarely, cerebrospinal fluid leakage from the nose

Eye and vision problems

• Blurred or double vision
• Loss of part of the visual field

How is empty sella syndrome diagnosed?

ESS is typically diagnosed through brain imaging; however, blood tests and eye examinations are also performed.

Imaging tests

• MRI scan: This is the most common and accurate test. The sella turcica appears filled with fluid, and the pituitary gland is seen as thin and flattened against the wall
• CT scan: This can also be used if an MRI is not possible. Whilst it can show changes in the sella turcica, it is generally considered less detailed than MRI

Other tests

Since ESS can affect hormone production, doctors may also perform:

• Blood tests: To check hormone levels and assess pituitary function
• Eye examinations: To check for vision changes, as the optic nerves are located close to the pituitary region

Why does diagnosis matter?

Even if ESS is found incidentally, it is important to determine whether the condition is benign or associated with hormonal or visual complications. This helps doctors decide whether further treatment or ongoing monitoring is required.

Empty sella syndrome after pituitary surgery

Why does it happen?

Surgery is often the first-line treatment for pituitary tumours, particularly transsphenoidal surgery, a method in which the doctor accesses the gland through the nose. However, it can alter the appearance of the pituitary region. After surgery, the space previously occupied by the tumour may fill with fluid, which presses the remaining pituitary tissue flat, making scans appear to show an “empty” sella. This is how secondary ESS can develop following surgery.

Risk factors

• Removal of a large tumour, leaving behind a larger empty space
• Damage or stretching of the diaphragma sellae, the thin membrane covering the pituitary
• Cerebrospinal fluid (CSF) leakage during surgery⁶

Empty sella syndrome after radiation therapy

Why does it happen?

Radiation therapy is often used when surgical methods are unsuccessful or when tumours recur. Newer techniques such as stereotactic radiosurgery allow doctors to target the tumour precisely whilst minimising exposure to surrounding structures. However, radiation can still inadvertently affect the pituitary gland, potentially causing it to shrink or become scarred, thereby reducing its functional capacity. As the gland diminishes in size, fluid can fill the sella turcica, leading to secondary ESS.

Risk factors

• The dose of radiation administered
• The size of the tumour
• The extent of the tumour treated
• Whether the patient has also undergone surgery, as combined treatment increases the risk

Why does empty sella syndrome matter?

ESS can cause significant symptoms, notably major hormonal changes, potential vision loss, and other long-term health complications. It is therefore important to address this syndrome as soon as it is identified. Unfortunately, in most cases, ESS is only discovered incidentally when scans are performed for other purposes. Furthermore, the syndrome can be asymptomatic in some individuals, which further complicates its diagnosis. This highlights the importance of raising awareness of ESS to ensure that affected patients receive appropriate care.

Hormone changes

• Fatigue, low energy, or weakness
• Weight changes or metabolic difficulties
• Irregular periods, fertility problems, or issues with sexual health
• Need for lifelong hormone replacement in some patients

Quality of life

• Frequent headaches
• Eye problems, which may interfere with work or daily activities
• Emotional or mood changes, linked to hormonal imbalance

Monitoring and care

• Regular blood tests to monitor hormone levels
• Brain imaging to confirm the absence of new tumour growth
• Vision tests if symptoms develop

Managing empty sella syndrome

When no treatment is needed

In most cases, ESS does not produce any signs or symptoms.⁷ If hormone levels are within normal range and there are no visual disturbances, doctors often recommend regular check-ups and imaging to ensure no changes have occurred.

Hormone management

If ESS affects pituitary function, patients may require hormone replacement therapy. This can include:

• Thyroid hormones: For energy regulation and metabolism
• Cortisol: For the body’s stress response
• Sex hormones: Such as oestrogen or testosterone
• Growth hormone: Particularly in younger patients

These treatments help to improve quality of life and maintain hormonal balance.

Monitoring vision and neurological health

Because ESS can sometimes affect the optic nerves or cause persistent headaches, doctors may also recommend:

• Regular eye examinations to monitor vision
• Neurological assessments if headaches or other symptoms persist

Long-term follow-up

Patients who have undergone pituitary surgery or radiation therapy require lifelong follow-up. This typically involves:

• Periodic MRI scans
• Routine blood tests to monitor hormone levels
• Adjustment of treatments as needed

Summary

ESS is a condition in which the pituitary gland appears flattened on brain imaging, giving the sella turcica an “empty” appearance. Whilst many individuals remain asymptomatic, others may experience hormonal changes, visual disturbances, or headaches. The condition may arise without a clear cause or may develop as a consequence of pituitary tumour treatment, including surgery or radiotherapy. Surgery can result in ESS shortly after the procedure, whilst radiation may induce gradual changes over time. Although ESS is not always associated with significant risk, its potential impact on hormonal function and vision makes regular monitoring essential. Through imaging, blood tests, and eye examinations, doctors can identify issues early and support long-term patient health.