Pituitary adenoma is a benign tumor in the pituitary gland. This gland is about the size of a pea and sits on a bony cavity at the base of the brain. It is considered the master gland that regulates the secretion of many important hormones throughout the body.

Pituitary adenomas represent approximately 10 percent of all brain tumors. They are classified based on what type of hormone is secreted by the tumor. If it is not secreting any hormone, it is termed a “non-functioning tumor.”

Symptoms
Many pituitary adenomas do not cause symptoms. However, if a tumor grows large enough, it can cause headaches and visual loss by pushing on nearby structures. If it pushes on the pituitary gland, symptoms can include low blood pressure, fatigue, weakness, symptoms of hypothyroidism and a decreased sex drive.

If the tumor secretes hormones, the symptoms depend on which hormones are being released.

• Adrenocorticotropic hormone (ACTH)
  • rounding of the face
  • stretch marks
  • hirsutism (facial male-pattern hair growth)
• Prolactin (also known as prolactinoma)
  • milky discharge from the breasts
  • irregular or absent menstrual periods
  • decreased sexual function
• Growth hormone
  • enlargement of the hands, feet, nose, lips and ears
  • change in ring or shoe size
  • lower jaw protrusion
  • change in facial appearance with brow protrusion

Diagnosis
Pituitary adenomas are usually diagnosed with an MRI scan, though large tumors can sometimes be seen on a CT scan. The tumor can also be diagnosed through blood tests for hormone levels.

Treatment
Pituitary adenoma treatment depends on several factors. Some are successfully treated with medication or radiation therapy. However, if the tumor is growing, compressing important structure or secreting hormones, it will require surgical resection. A variety of surgical approaches are available. A majority of the tumors can now be accessed through the nose (transnasal transsphenoidal approach) using endoscopes or microscopes.

Recovery
The prognosis for the treatment or removal of pituitary tumors is excellent. However, any damage done by the tumor, such as visual loss, cannot be repaired. Also, hormonal deficiencies caused by tumor compression cannot be reversed and hormonal supplements may be required.