6 things to know about pituitary adenomas

Pituitary adenomas, also referred to as pituitary neuroendocrine tumors, are almost always benign tumors that arise from hormone-secreting cells in the pituitary gland. 

This gland is situated at the base of the brain, just behind the bridge of the nose, inside a bony cave called the sella turcica. The pituitary gland is considered the “master” gland because it controls all the other hormone-producing glands in the body. 

But are pituitary adenomas ever cancerous? What are their symptoms? And, how are they typically treated? Keep reading to learn the answers to these and other questions I sometimes hear about pituitary adenomas. 

Are pituitary adenomas ever cancerous?  

Pituitary adenomas are benign by definition. That means they are not cancerous. And, despite their location, they are not considered a type of brain tumor.

Very rarely, pituitary adenomas can spread to other parts of the body. At that point, though, they are called something else: pituitary carcinomas. 

Do pituitary adenomas ever cause symptoms? 

Yes. There are two broad categories of pituitary adenomas: functioning and non-functioning.  

Functioning tumors  

These make too much of certain hormones that travel to other glands and affect how they behave. People’s symptoms vary based on the type of hormone being produced. 

• Prolactinoma: Prolactin, also known as “the breast milk hormone,” can suppress the function of the gonads (ovaries in women and testes in men). Too much of it may cause decreased libido (chiefly men) and infertility (both sexes), missed periods (women), milky breast discharge (women, and very rarely men), and impotence and loss of body hair (men). 
• Adrenocorticotropic hormone (ACTH): Too much ACTH leads to excessive production of cortisol, a condition called Cushing disease. Too much cortisol can cause weight gain (especially in the center part of the body), excessive fat deposits above the collar bones and upper back, a rounded face, thin skin, easy bruising, stretch marks, ankle swelling, osteoporosis, diabetes, and high blood pressure.
• Growth hormone: Too much of this hormone can lead to a condition called acromegaly, in which the soft tissues in the hands and feet become abnormally large. Other issues include facial and jaw changes, excessive sweating, heart disease, high blood pressure, joint pains/arthritis, sleep apnea, and diabetes.  
• Thyroid-stimulating hormone (TSH): Too much of this hormone can cause weight loss, anxiety, trouble sleeping, feeling too hot, and a rapid and sometimes irregular heartbeat. 

Non-functioning tumors  

These pituitary adenomas don’t secrete any hormones, so they’re considered “silent.” Once a non-functioning pituitary adenoma gets large enough, however, it can start compressing the optic chiasm. This may cause vision changes, especially along the sides of the visual fields, also known as peripheral vision. 

Non-functioning tumors may also cause headaches and abnormally low hormone levels. 

How are pituitary adenomas usually diagnosed? 

Most patients with functioning pituitary adenomas are diagnosed when they start to experience symptoms and physical changes that lead to an assessment by a doctor. Then, imaging finds the tumor.  

Patients with non-functioning pituitary adenomas, on the other hand, typically notice peripheral vision loss, headaches, or symptoms of low hormone levels first, which then leads to a brain MRI that reveals the tumor.  

Finally, some people only find out they have a pituitary adenoma by accident when they’re getting a brain scan for some other reason. This is called an incidental finding. 

How are pituitary adenomas typically treated? Do they have to be removed? 

Pituitary adenomas are not life-threatening. Depending on their type, they can be treated with surgery, medication, and sometimes radiation therapy. 

Prolactinomas, for example, can usually be treated with medicine alone. Surgery is another good option for people with small prolactinomas who prefer surgery over medication and for those who do not tolerate medication very well. 

For all other functioning tumors, surgery is usually considered first, followed by additional treatment to lower hormone levels if surgery is not curative.   

For non-functioning tumors, surgery is usually undertaken to improve vision and alleviate headaches. However, small, incidentally discovered non-functioning tumors may be monitored without therapy in patients who display no symptoms. 

Finally, radiation therapy is sometimes needed to control tumor growth and/or treat excessive hormone production when other treatments don’t work.

 What is the life expectancy of a person with pituitary adenoma? 

Pituitary adenomas can lead to a shorter lifespan if the hormonal problems they cause are not well-controlled. However, with proper treatment, life expectancy for patients with pituitary adenomas is the same as anyone else’s.

What’s the most important thing to know about pituitary adenomas? 

Pituitary adenomas and carcinomas are unique tumors that often require multidisciplinary expertise to treat them. Therefore, it is vital for every patient diagnosed with a pituitary tumor to consider being treated at a pituitary tumor center of excellence, such as MD Anderson.

A lot of people don’t realize this, simply because our name contains the word “cancer,” but MD Anderson also provides excellent care to patients with benign tumors.  

Steven Waguespack, M.D., is an endocrinologist specializing in pituitary tumors, thyroid cancer and multiple endocrine neoplasia.  

Request an appointment at MD Anderson online or call 1-877-632-6789.