Pituitary Tumors

What causes this condition?

Pituitary tumors are abnormal growths in the pituitary gland - a small gland within the brain that secretes various hormones. These tumors, which make up 10% of cancers in the skull, originate most often in the front of the pituitary (called the adenohypophysis). They occur in adults of both sexes, usually during the third and fourth decades of life. The prognosis is fair to good, depending on the extent of tumor spread.

What causes it?

Although the exact cause is unknown, a predisposition to pituitary tumors may be inherited.

What are its symptoms?

As a pituitary adenoma grows, it enlarges the sella turcica, which contains the pituitary gland. Symptoms reflect the tumor's effect on both neurologic and endocrine function.

Neurologic symptoms

• Headache

• Blurred vision progressing to visual field defects and then blindness In one eye

• Eye or gaze deviation, double vision, nystagmus, ptosis, limited eye movement

• Increased pressure inside the skull

• Personality changes or dementia

• Seizures

• Runny nose

• Hemorrhage in the pituitary gland, possibly causing both cardiovascular and adrenocortical collapse

Endocrine symptoms

• Cessation of menses, reduced sex drive, impotence, discolored or waxy skin or fewer wrinkles, loss of armpit and pubic hair, lack of energy, weakness, easily fatigued, cold intolerance, constipation

• Addisonian crisis precipitated by stress and resulting in nausea, vomiting, low blood sugar, decreased blood pressure, circulatory collapse

• Diabetes insipidus

• Galactorrhea, acromegaly, and Cushing's syndrome

How is it diagnosed?

• Skull X-rays with tomography show enlargement of the sella turcica or erosion of its floor, if growth hormone secretion predominates, X-rays show enlarged paranasal sinuses and mandible, thickened cranial bones, and separated teeth.

• Carotid angiography shows displacement of the anterior cerebral and internal carotid arteries if the tumor is enlarging; it also rules out intracerebral aneurysm.

• Computed tomography scan (commonly called a CAT scan) may confirm the existence of the adenoma and accurately depict its size.

• Cerebrospinal fluid analysis may show increased protein levels .

• Endocrine Junction tests may contribute helpful information, but results are often ambiguous and inconclusive.

How is it treated?

Surgical options include transfrontal removal of a large tumor impinging on the optic apparatus and transsphenoidal resection for a smaller tumor confined to the pituitary fossa.

Radiation is the primary treatment for small, nonsecretory tumors that don't extend beyond the sella turcica or for people who may be poor surgical risks; otherwise, it's used as an adjunct to surgery.

Postoperative treatment includes hormone replacement with cortisone, thyroid hormone, and sex hormones; correction of electrolyte imbalances; and insulin therapy as needed.

Drug therapy may include bromocriptine, which shrinks prolactin-secreting and growth hormone-secreting tumors, and cyproheptadine, which can reduce corticosteroid levels in the person with Cushing's syndrome.

Adjuvant radiation therapy is used when only partial removal of the tumor is possible. Freezing the area with a probe inserted transsphenoidally is a promising alternative to surgical dissection of the tumor.