Pituitary tumors are abnormal growths that develop in the pituitary gland. The pituitary gland is a small gland located near the brain that regulates the body’s balance of hormones. Some pituitary tumors cause an increased production of hormones while others can restrict normal functions of the pituitary gland, causing it to produce lower levels of hormones.
Most pituitary tumors are noncancerous growths called pituitary adenomas, which stay within the pituitary gland and don’t spread to other areas of the body. However, the tumor can put pressure on nearby structures, such as optic nerves, in turn limiting an individual’s eyesight.
Treatment options for pituitary tumors typically involves managing hormone levels with medications, controlling the growth of the tumor and surgery to remove the tumor itself.
There are two different types of pituitary tumors: macroadenomas and microadenomas. Macroadenomas are large pituitary tumors (about 1 centimeter) that can put pressure on the rest of the pituitary gland and nearby areas, while microadenomas are smaller tumors.
Signs and symptoms of pressure from a pituitary tumor may include:
· Loss of eyesight
· Nausea and vomiting
· Hormone deficiency
· Changes in a woman’s menstrual cycle
· Loss of body hair
· Sexual dysfunction
· Constant need to urinate
· Unintentional weight loss or gain
A pituitary tumor causes symptoms in different ways, by producing too much of one or more hormones.
- Adrenocorticotropic hormone-secreting tumors (ACTH) can cause high blood pressure, high blood sugar levels, muscle weakness, easy bruising, stretch marks, thinning of the skin and emotional changes
- Growth hormone-secreting tumors can cause enlarged hands and feet, high blood sugar levels, increased sweating, pain in the joints, heart disease, increased body hair growth, and sleep apnea
- Prolactin-secreting tumors can cause inappropriate secretion of breast milk, bone weakening, loss of sex drive, infertility, irregular menstrual periods and erectile dysfunction in men.
- Thyroid-stimulating hormone-secreting tumors can cause unintentional weight loss, fast heart rate, frequent bowel movements, nervousness, increased sweating and feeling warm or hot.
The causes of pituitary tumors remains unknown. The pituitary gland is a small gland located at the base of the brain that regulates the body’s balance of many hormones. The hormones help control important functions such as growth, blood pressure and reproduction. Uncontrolled cell growth in the pituitary gland creates a tumor that can influence how the hormones work (some may be produced more, produced less or even get damaged). Researchers suspect that genetic changes play an important role in how pituitary tumors develop.
Although pituitary tumors can occur at any age, they're most likely to occur in older adults. The only known risk factors for pituitary tumors are:
Multiple endrocine neoplasia type 1 (MEN1): Families with a history of MEN1 have an increased risk of pituitary gland tumors
Carney complex: A genetic condition that can increase the risk of a pituitary gland tumor.
Familial acromegaly: A condition in adults caused by too much growth hormone.
Complications that can arise from pituitary tumors can include the following:
- Loss of eyesight due to pressure on the optic nerves
- Permanent hormone deficiency
- Diabetes insipidus
Since pituitary tumors can cause serious problems by putting pressure on the brain, treatment is often necessary. Treatment options for a pituitary tumor depends on the type of tumor, its size and how far it has grown into the brain.The two main surgical techniques for treating pituitary tumors are:
· Endoscopic transnasal transsphenoidal approach: Surgical removal of the tumor through the nose and sinuses without an external incision.
· Transcranial approach (craniotomy): Surgical removal of the tumor through the upper part of the skull by way of incision in the scalp.
Other treatment methods may include radiation therapy:
- External radiation: The use of high energy X-rays to destroy tumors. A series of treatments, usually five times a week over a four- to six-week period, is performed on an outpatient basis. This form of treatment is usually beneficial if a tumor persists or returns after surgery.
- Gamma Knife stereotactic radiosurgery: The use of radiation beams specifically on the tumor without an incision. A minimal amount of radiation comes in contact with healthy tissue surrounding the tumor, decreasing the risk of damage to normal tissue.
Treatment methods with medications may help to block excess hormone secretion and sometimes shrink certain types of pituitary tumors:
· Bromocriptine (Parlodel, Cycloset) and cabergoline drugs can help treat prolactin-secreting tumors (prolactinomas) by decreasing prolactin secretion and often reducing the size of the tumor. Possible side effects may include sleepiness, faintness, vomiting, diarrhea, confusion and depression.
· Somatostatin analogs drugs (Sandostatin, Somatuline Depot, others) can help decrease growth hormone production and reduce the size of the tumor. These drugs are useful if surgery has been unsuccessful in normalizing growth hormone production. Possible side effects may include stomach pain, vomiting, faintness, headache and diarrhea.
Watchful waiting (observation):
In watchful waiting, regular follow up tests are used to monitor and control the growth of pituitary tumors. Individuals who are older or in poor health usually choose this method if the tumors do not cause additional problems. In younger adults, the tumor is carefully monitored to see if any changes might arise that may require treatment such as surgery.