Pituitary Adenomas

Pituitary adenomas are noncancerous tumors that form in the pituitary gland, a small but important gland located at the base of the brain. The pituitary gland is the main central regulator of our hormones. Hormones control metabolism, sexual function, reproduction, onset of puberty and our stress responses. Pituitary adenomas are generally benign (noncancerous), but they can significantly impact a person’s health by either pressing on nearby structures, which can reduce essential hormones or lead to excess hormone levels.

These tumors account for about 10–15% of all brain tumors and are typically slow-growing. With early detection and proper treatment, pituitary adenomas are often manageable and, in many cases, curable.

What Are Pituitary Adenomas?

A pituitary adenoma is a tumor of the pituitary gland, which sits in a bony cavity called the sella turcica, between the eye socket and the back of the nasal cavity. These tumors are classified into two main types, functioning and non-functioning, as well as by size, microadenomas and macroadenomas.

Functioning Adenomas

Functioning adenomas produce abnormal levels of hormones that can cause endocrine disorders.

• Functioning adenomas that produce excess prolactin are known as prolactinomas. They can cause infertility.
• Functioning adenomas that secrete increased levels of cortisol can cause Cushing’s disease.
• Functioning adenomas that produce too much growth hormone (ACTH) can cause acromegaly.
  
  

Non-Functioning Adenomas

Nonfunctioning adenomas do not produce hormones. Their primary impact is from their size, as they can compress surrounding brain structures – particularly the optic nerve and optic chiasm – leading to problems with vision.

Categorized by Size

• Microadenomas: Tumors less than 10 mm in diameter.
  
• Macroadenomas: Tumors larger than 10 mm, more likely to cause pressure symptoms.
  
  

Who Gets Pituitary Adenomas and When?

Pituitary tumors can affect people of any age, but they are most commonly diagnosed in adults between ages 30 and 60. They occur slightly more frequently in women, especially prolactin-secreting tumors.

Pituitary adenomas are rarely inherited, although certain genetic conditions, such as multiple endocrine neoplasia type 1 (MEN1), can increase the risk.

What Causes Pituitary Adenomas?

The exact cause of pituitary adenoma tumors is not fully understood. These tumors are generally sporadic, arising from spontaneous genetic mutations in the cells of the pituitary gland.

Some research suggests a role for inherited genetic changes, particularly in rare familial cases.

What Are the Causes and Risk Factors of Pituitary Adenomas?

Most pituitary gland tumors develop without any known cause, but several risk factors may increase susceptibility:

• Genetic syndromes like MEN1
• Family history of pituitary or endocrine tumors (rare)
• Gender: Certain types are more common in women
• Age: Most often found in adults between 30 and 60 years old

What Are the Signs and Symptoms of Pituitary Adenomas?

Symptoms depend on whether the tumor is functioning (hormone-producing) or nonfunctioning and whether it causes mass effect on surrounding tissues.

Functional Adenoma Signs & Symptoms

Symptoms caused by hormone overproduction:

• Prolactinoma (excess prolactin):
  
  • Irregular menstrual cycles
  • Infertility
  • Galactorrhea (unexpected milk production)
  • Erectile dysfunction in men
    
    
• Cushing’s disease (excess ACTH):
  
  • Weight gain, particularly in the face and abdomen
  • Acne in skin rashes
  • High blood pressure
  • Muscle weakness
  • Mood changes
    
    
• Acromegaly (excess growth hormone):
  
  • Enlarged hands and feet
  • Joint pain
  • Facial feature changes
  • Diabetes
    
    

Non-Functional Adenoma Signs & Symptoms

Symptoms caused by tumor size (macroadenoma):

• Headaches
• Vision changes, especially loss of peripheral vision
• Fatigue
• Nausea and vomiting
• Hormonal deficiencies (if the tumor interferes with normal pituitary function)

How Are Pituitary Adenomas Diagnosed?

Diagnosis of a pituitary tumor involves a combination of clinical evaluation, hormone testing, and advanced imaging:

• Blood and urine tests: To assess hormone levels (prolactin, ACTH, cortisol, GH, FSH, IGF-1, TSH, etc.)
• MRI of the brain: The gold standard for visualizing pituitary tumors
• Visual field testing: To detect vision impairment caused by tumor pressure on the optic nerves
• Stimulation/suppression hormone tests: Used to evaluate hormone secretion behavior
  
  

Early diagnosis improves treatment outcomes and reduces the risk of long-term complications.

How Are Pituitary Adenomas Treated?

Treatment for pituitary adenomas is highly individualized based on tumor type, size, hormone activity and the presence of symptoms. Management options include transsphenoidal surgery, radiosurgery and medications for prolactinoma.

Radiation Therapy & Radiosurgery
Radiation is an option when:

• Surgery is not possible or does not completely remove the tumor
• The tumor recurs
• Hormone levels remain elevated despite surgical treatment
  
  

Radiation therapy for pituitary adenomas includes:

• Stereotactic radiosurgery (Gamma Knife): Delivers highly focused radiation to the tumor in a single treatment
  
• Stereotactic radiotherapy: Used when the tumor is close to sensitive structures like the optic nerves. This is similar to Gamma Knife, but the treatments is divided into 5 separate visits.
  
  

Surgical Treatment
Surgery is often recommended for:

• Nonfunctioning macroadenomas causing vision problems
• Functioning tumors when immediate control of hormone levels is essential
• Tumors suspected of being malignant (rare)
  
  

Transsphenoidal surgery—a minimally invasive approach through the nasal cavity—is the most common and effective surgical technique for pituitary adenomas. In rare cases, craniotomy may be necessary.

Postoperative follow-up includes hormone monitoring, imaging, and, if needed, additional therapy.

Medical Treatment
Medications are often the first-line treatment for functioning tumors, particularly prolactinomas. In prolactinomas, medications may reduce tumor size and hormone levels without the need for surgery.

• Dopamine agonists (e.g., cabergoline, bromocriptine): Shrink prolactin-secreting tumors and normalize hormone levels
• Somatostatin analogs and GH receptor antagonists: Used to manage acromegaly if growth hormone levels remain elevated after surgery
• Adrenal-suppressing drugs: Help control symptoms in Cushing’s disease when surgery does not cure the condition

Advanced Care for Pituitary Tumors

If you or a loved one has been diagnosed with a pituitary adenoma, our expert team is here to provide cutting-edge care and compassionate support.

Contact us today to schedule an appointment or learn more about your treatment options.