Observation for Pituitary Tumors

Most pituitary tumors are benign, slow growing, and non-cancerous. A fraction of pituitary tumors are non-functioning, meaning they do not disturb hormones of the pituitary gland. In certain cases, your surgeon may elect to monitor your tumor over time and choose to pursue surgical avenues when tumor growth is evident on follow-up imaging.  

Here, we’ll discuss frequently asked questions about the observation of small and non-functional pituitary tumors.

A pituitary tumor will not go away on its own, but this does not necessarily mean it will require immediate treatment. Not all pituitary tumors cause symptoms. Non-functioning pituitary tumors are clinically silent and may go undetected for years or may never even be discovered at all.

While these tumors may not disappear, they may grow at a very slow rate or stop growing altogether for a while. It is possible to observe asymptomatic non-functioning pituitary tumors in certain cases. Patients of advanced age and those with medical problems, which increases the risk when undergoing surgery and anesthesia, may find value in regular followups as a first-choice management strategy.

Many pituitary tumors are discovered during routine workup for an unrelated issue. For example, it’s not uncommon for a patient in the emergency department to undergo a computed tomography (CT) scan of the head after a fall, only to realize a mass near the pituitary gland. Once you are aware of a tumor, it’s best to seek care as soon as possible. Your family doctor is likely to refer you to an endocrinologist or neurosurgeon.

Although some patients may not know they have a pituitary tumor at all if it is not causing any symptoms, other patients notice small changes over time that, in hindsight, signal that a potential problem should be evaluated. Severe symptoms that disrupt your everyday life should be evaluated as soon as possible. Gradual changes consistent with the presence of a pituitary tumors may be subtle. Some common signs of pituitary tumors to watch for include: 

• Frequent headaches or vision problems
• Frequent tiredness, irritability, or other mood changes
• Changes to your reproductive system that result from the changes to your hormone levels, such as changes to your menstrual cycle, fertility, or erectile function
• Weight gain, high blood pressure, and bruising (i.e., signs of Cushing's syndrome)
• Unusual growth of the arms, legs, skull, and jaw that result from hormonal changes

Treatment, rather than observation, is the mainstay of managing growing or large pituitary tumors. The decision to observe a pituitary tumor is not made lightly. If your doctor determines that your tumor is small and causing no disruption to your daily life, then observation may be a reasonable alternative to immediate treatment.

Your neurosurgeon or endocrinologist will likely establish a regular testing schedule to monitor your tumor and condition over time, usually via MRI scans every year. If your tumor remains small, not growing, and not producing any hormones, you may not need surgery. This also applies to patients of advanced age with clinically insignificant tumors that remain slow growing or stop growing over time.

Pituitary tumors with a diameter of approximately one centimeter or less are generally the most likely to be observed without immediate intervention, but the size of your tumor is only one of several factors that will help your doctor determine whether surveillance is an appropriate option instead of medication or another form of treatment. 

You will likely have an appointment once per year to monitor your pituitary tumor. These appointments will generally consist of an MRI scan to monitor the size, shape, and other physical features of the tumor. Blood work may also be necessary to measure hormone levels that may lead to the development of new or more serious symptoms. Minor changes between tests are to be expected and may not mean that you’ll need medication, radiation therapy, or surgery, but gradual changes over time may indicate that you are becoming more likely to need treatment in the future and might signal the need for more frequent monitoring.

Some patients may need to undergo evaluation of their vision every 6 months to make sure their sizable tumor is not causing any new visual compromise.

Significant differences between consecutive tests while under surveillance may mean that it is time to begin treatment. Some pituitary tumors, e.g., prolactinomas, that require treatment can be successfully managed with medication alone. Only approximately 10% of these tumors will ultimately require surgery or other intervention. 

It is possible for pituitary tumors to recur. This recurrence could occur even 20 or more years later after treatment, although this is less common than earlier recurrences. This means that some degree of monitoring will be necessary for years following successful pituitary tumor treatment for the best chance of catching a secondary tumor development as early as possible.

Monitoring that follows pituitary tumor treatment will generally consist of regular MRI scans and blood work, much like monitoring a benign pituitary tumor that is not causing any problems. Both types of monitoring aim to catch potential problems while they are easier to treat, as both original and recurring pituitary tumors that eventually require surgery, medication, or another form of treatment generally respond better when treatment is not delayed. 

Observing and monitoring pituitary tumors rather than treating them is a reasonable option for some patients with pituitary tumors that are small, not causing any pressure symptoms, and not producing any abnormal level of hormones. Monitoring can be a viable option for helping the right patient live a life that is as normal as possible. Your endocrinologist and neurosurgeon as well as other members of your care team are critical resources when it comes to evaluating every aspect of your pituitary tumor to determine what option is best for you. 

• Pituitary tumors will not go away on their own, but they do not always require treatment.
• Most pituitary tumors are benign.
• Regular monitoring of pituitary tumors is critical if immediate treatment is not necessary.

• Pituitary Network Association 
• National Brain Tumor Society
• American Brain Tumor Association 
• Pediatric Brain Tumor Foundation
• Endocrine Society 
• Pituitary Foundation 
• Cushing’s Support & Research Foundation