Pituitary Tumors Information

Pituitary tumors are abnormal growths on the pituitary gland. Some tumors secrete hormones normally made by the pituitary gland. Pituitary tumors originate most often in the anterior pituitary (adenohypophysis) and constitute 10% of intracranial neoplasms. They occur in adults of both sexes, usually between ages 30 and 40.

The most common tumor tissue types include chromophobe adenoma (90%), basophil adenoma, and eosinophil adenoma. As pituitary adenomas grow, they replace normal glandular tissue and enlarge the sella turcica, which houses the pituitary gland. The prognosis is fair to good, depending on the extent to which the tumor spreads beyond the sella turcica.

Pituitary tumors are also associated with certain hereditary disorders.

Causes

The exact cause is unknown, but a predisposition to a pituitary tumor may be inherited through an autosomal dominant trait. A pituitary tumor isn't malignant in the strict sense; however, its invasive growth categorizes it as a neoplastic condition.

Chromophobe adenoma may be associated with production of corticotropin, melanocyte-stimulating hormone, growth hormone, and prolactin; basophil adenoma, with excess corticotropin production and, consequently, with Cushing's syndrome; and eosinophil adenoma, with excessive growth hormone.

Signs and Symptoms

Symptoms vary depending upon what type of tumor is growing and what area of the pituitary gland is affected. Pituitary tumors can cause symptoms which are associated with excess production of pituitary hormones and symptoms associated with reduced production of pituitary hormones. Each individual also experiences symptoms differently, and the symptoms many resemble other conditions or medical problems. Always consult your physician for a diagnosis.

Diagnostic tests 

In addition to a complete medical history and medical examination, diagnostic procedures for pituitary tumors may include:

• measurement of hormone levels in the blood
• computed tomography (CT or CAT scan) - a non-invasive procedure that takes cross-sectional images of the brain or other internal organs; to detect any abnormalities that may not show up on an ordinary x-ray
• magnetic resonance imaging (MRI) - a non-invasive procedure that produces two-dimensional views of an internal organ or structure, especially the brain or spinal cord

Treatment

Surgical options include transfrontal removal of large tumors impinging on the optic apparatus and transsphenoidal resection for smaller tumors confined to the pituitary fossa. Radiation therapy is the primary treatment for small, nonsecretory tumors confined to the sella turcica or for patients considered poor surgical risks. Otherwise, radiation is an adjunct to surgery, especially when only part-of the tumor can be removed.

Postoperative measures include replacement therapy with corticosteroids or thyroid or sex hormones, correction of electrolyte imbalances and, as necessary, insulin therapy. Other drug therapy may include bromocriptine, an ergot derivative that shrinks prolactin­secreting and growth hormone-secreting tumors. Cypro­heptadine, an antiserotonin drug, can reduce increased corticosteroid levels in Cushing's syndrome.

Cryohypophysectomy (freezing the area with a probe inserted transsphenoidally) is an alternative to surgical resection.

Prognosis

Pituitary tumors are usually curable. Following surgery, adults may gradually resume their normal activities, and children may return to school when the effects of the operation have diminished, and appetite and sense of well-being have returned. Patients should wear medical identification tags identifying their condition and the hormonal replacement medicines they take.