Non Functioning Pituitary Adenoma
What is a Non-Functioning Pituitary Adenoma?
Overview
Endocrine-inactive adenomas do not result in excess hormone production. Instead, they typically cause symptoms due to pressure on the normal pituitary gland and/or on structures near the pituitary such as the optic nerves and optic chiasm. Endocrine-inactive or non-functional pituitary adenomas typically cause headaches, visual loss or loss of pituitary hormonal function.
For the great majority of patients with a symptomatic endocrine-inactive adenoma and for most incidentally discovered adenomas over 15 mm in size, transsphenoidal surgical removal (via the nose) is the treatment of choice. Fortunately, there have been major technical advances in this surgical approach, including use of high-definition endoscopic visualization, surgical navigation techniques and more effective skull base closure methods.
For patients with adenomas that cannot be completely removed with endoscopic surgery, focused radiosurgery or radiotherapy is delivered to tumors to halt their growth.
For patients with particularly invasive and aggressive adenomas (atypical adenomas or pituitary carcinoma), we can offer novel clinical trials and tumor genetic sequencing to provide therapies beyond traditional surgery and radiation treatments. Tailored hormone replacement therapy is also provided.
Who is Affected?
Non-functioning pituitary adenomas can occur in both men and women, most often between the ages of 30 and 60. They account for approximately one-third of all pituitary adenomas. While many are discovered incidentally on imaging performed for other reasons, larger tumors are more likely to cause symptoms that lead to diagnosis. People with a family history of pituitary tumors or genetic conditions like multiple endocrine neoplasia type 1 (MEN1) may have an increased risk.
Non-Functioning Pituitary Adenoma Symptoms & Causes
Symptoms
Typical complaints of patients with an endocrine-inactive adenoma often include:
- Vision loss
- Headache
- Hypopituitarism – symptoms may include:
- Fatigue
- Decreased mental function
- Weight gain
- Lethargy
- Joint pain
- Loss of sex drive
- Infertility
- In women, irregular periods or amenorrhea
Almost all symptomatic endocrine-inactive adenomas are macroadenomas. Occasionally, these tumors grow quite large and extend into the cavernous sinus, leading to nerve compression and double vision.
Some patients with large tumors may experience hemorrhage into the tumor (pituitary apoplexy), which can cause the rapid onset of headache, vision loss, double vision, and/or pituitary failure.
Causes
The exact cause of non-functioning pituitary adenomas is not fully understood. These tumors arise from genetic mutations in pituitary cells that cause them to grow abnormally, but they do not secrete excess hormones. Most are sporadic (not inherited), but some may be associated with genetic syndromes such as MEN1.
When to See a Doctor
Seek medical attention if you experience:
- Persistent headaches
- Vision changes, including blurry or double vision
- Unexplained fatigue, weight changes, or hormonal symptoms
- Loss of menstrual periods or fertility issues
- Sudden severe headache or visual changes (possible sign of pituitary apoplexy, a medical emergency)
Non-Functioning Pituitary Adenoma Diagnosis
Endocrine-inactive adenomas are diagnosed by imaging studies and hormonal testing. An MRI of the pituitary gland provides the most detail, although a brain MRI or brain CT scan will reveal most pituitary macroadenomas. Hormonal testing is also essential to evaluate for pituitary gland failure (Hypopituitarism). A complete pituitary hormonal analysis should be performed as described above and is ideally overseen by an endocrinologist.
Non-Functioning Pituitary Adenoma Treatment & Outcomes
Treatment Options
Endoscopic Endonasal surgery is the first-line therapy for most Pituitary Adenomas.
Transsphenoidal surgery is considered first-line treatment for symptomatic endocrine-inactive adenomas and most incidentally discovered adenomas over 15 mm in size, particularly if they compress the optic nerves or optic chiasm. Because of improved visualization, the endoscopic endonasal approach has become the preferred method for removal of pituitary adenomas, including endocrine-inactive adenomas. The long-term surgical remission or cure rate is 70-80% overall. Complete tumor removal is more likely with smaller tumors and those that do not invade the cavernous sinus or skull base; complete removal rates are lower for larger (over 3 cm) and invasive adenomas. Endonasal tumor removal improves visual acuity and visual field deficits in 75-90% of patients and headache resolution is typically seen in over 80% of patients. Pituitary function is improved in 20-50% of patients while new pituitary failure may occur in 5% of patients. Patients who do not have hormonal recovery after surgery will require hormone replacement therapy. Major surgical complications after endoscopic endonasal surgery such as vision loss, bleeding, stroke, cerebrospinal fluid leak and meningitis are quite low when performed by an experienced surgical team such as ours at the Pacific Pituitary Disorders Center. Because of the excellent panoramic visualization provided by the endoscope, it is rare (1% or less) that pituitary adenomas warrant a craniotomy for removal.
For patients who have residual tumor after the initial endoscopic surgery, focused radiation with SRS or SRT may be needed to control tumor growth; both treatment methods are highly effective in halting tumor growth in at least 85-90% of patients. However, SRT and SRS may result in loss of normal pituitary function over 5 to 10 years. Overall, focused radiosurgery and radiotherapy are considered very safe and effective treatments for patients with residual endocrine-inactive pituitary adenomas; neurologic complications such as visual loss and temporal lobe damage rarely occur with SRT and SRS.
There is no standard or FDA-approved medical therapy that reliably halts growth of endocrine-inactive adenomas. In some patients with aggressive adenomas, we will utilize the oral chemotherapy agent Temozolomide (Temodar) which can slow or stop growth in a minority of patients. More recently however, in such challenging cases of atypical adenomas or invasive typical adenomas, we recommend adenoma genetic sequencing to identify possible therapeutic targets. Our Director of Neuro-oncology, Dr. Santosh Kesari leads this effort and is a world expert in novel clinical trials for brain and skull base tumors.
Patient Outcomes
With proper treatment, most patients experience significant relief of symptoms, particularly improvement in vision and headaches. Long-term tumor control rates are high with combined surgery and radiosurgery. Hormonal function may improve in some patients, but ongoing hormone replacement may be needed. Regular imaging and endocrinology follow-up are important to monitor for tumor recurrence or delayed complications.
Managing A Non-Functioning Pituitary Adenoma
After initial treatment, ongoing care is important to maintain hormone balance, monitor for recurrence, and address any new symptoms. Patients often benefit from:
Lifelong Endocrinology Follow-Up
For hormone replacement and pituitary function monitoring
Regular MRI Scans
To ensure tumor stability
Vision Assessments
For patients with prior optic nerve compression
Access to Support Resources
For managing the long-term effects of pituitary disease
Meet our Expert Specialists & Surgeons
Experience Compassionate, Expert Care
At the Pacific Pituitary Disorders Center, we have one of the world’s largest experiences in endoscopic endonasal transsphenoidal surgery. By incorporating leading-edge technology and instrumentation with proven surgical experience of over 2000 endonasal surgeries, we make pituitary adenoma surgery safer, less invasive and more effective. We have one of the largest surgical experiences treating patients with newly diagnosed pituitary adenomas as well as patients with persistent or recurrent adenomas after prior surgery or radiation.
Learn More About a Non-Functioning Pituitary Adenoma
Non-functioning pituitary adenomas do not produce excess hormones, so their symptoms usually come from pressure on surrounding structures. Common symptoms include headaches, vision problems (especially loss of peripheral vision), fatigue, weight gain, low sex drive, infertility, irregular or absent periods in women, and in some cases, double vision. Very large tumors or sudden bleeding into the tumor (pituitary apoplexy) can cause severe headache and sudden vision loss.
Functioning pituitary adenomas produce excess hormones, leading to specific conditions like Cushing’s disease (excess cortisol) or acromegaly (excess growth hormone). Non-functioning pituitary adenomas do not produce hormones, so they typically don’t cause hormone-related symptoms. Instead, they cause problems due to their size and pressure on the normal pituitary gland, optic nerves, or nearby brain structures.
Non-functioning pituitary microadenomas (tumors less than 10 mm in size) often do not cause symptoms and are usually found incidentally. In many cases, no immediate treatment is needed. Instead, your doctor will recommend regular monitoring with MRI scans and hormonal testing. If the tumor grows, causes symptoms, or affects vision, treatment such as surgery may be considered.
The mortality rate for non-functioning pituitary adenomas is very low when appropriately treated. These tumors are typically benign (non-cancerous). With modern surgical techniques, radiosurgery, and hormone replacement therapy, most patients live a normal life expectancy. However, untreated large tumors can lead to serious complications, including vision loss and severe hormonal deficiencies.
Growth rates vary. Many non-functioning adenomas grow slowly over years, while others remain stable and do not grow at all. Rarely, some may grow more quickly or behave more aggressively. Regular follow-up with MRI scans and endocrinology evaluations is essential to monitor for changes over time.
Yes, it is possible to live without a fully functioning pituitary gland, but lifelong hormone replacement therapy is required. The pituitary gland regulates critical hormones for metabolism, growth, reproduction, and stress response. When it is damaged or removed, these hormones must be replaced with medications to maintain health and prevent complications.
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Get Expert Care from Leading Specialists
Our multidisciplinary team at the Pacific Pituitary Disorders Center specializes in diagnosing and treating non-functioning pituitary adenomas. We combine advanced surgical techniques, personalized hormone management, and access to clinical trials to provide comprehensive care for every patient.
Written and reviewed by:
The Pacific Neuroscience medical and editorial team
We are a highly specialized team of medical professionals with extensive neurological and cranial disorder knowledge, expertise and writing experience.
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