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• Intracranial and Spinal Tumors
4

Most pituitary tumors are adenomas. Symptoms include headache and endocrinopathies; endocrinopathies result when the tumor produces hormones or destroys hormone-producing tissue. Diagnosis is by MRI. Treatment includes correction of any endocrinopathy and surgery, radiation therapy, or dopaminergic agonists.

Most tumors of the pituitary and suprasellar region are pituitary adenomas. Rarely, pituitary tumors are carcinomas. Meningiomas, craniopharyngiomas, metastases, and dermoid cysts may also develop in the region of the sella turcica.

Adenomas may be secretory or nonsecretory. Secretory adenomas produce pituitary hormones; many secretory adenomas are < 10 mm in size (microadenomas). Secretory adenomas can be classified by histologic staining characteristics (eg, acidophilic, basophilic, chromophobe [nonstaining]). The hormone produced often correlates with these characteristics; eg, acidophilic adenomas overproduce growth hormone, and basophilic adenomas overproduce ACTH. The hormone most commonly overproduced is prolactin.

Any tumor that grows out of the pituitary can compress optic nerve tracts, including the chiasm. Tumors may also compress or destroy pituitary or hypothalamic tissue, impairing hormone production or secretion.

Symptoms and Signs

Headache may result from an enlarging pituitary adenoma, even when intracranial pressure is not increased. Visual manifestations such as bitemporal hemianopia, unilateral optic atrophy, and contralateral hemianopia may develop if a tumor compresses optic nerve tracts (see Fig. 1: Optic Nerve Disorders: Higher visual pathways—lesion sites and corresponding visual field defects.).

Many patients present with an endocrinopathy due to hormone deficiency or excess:

• Diabetes insipidus if less vasopressinSome Trade Names
  PITRESSIN
  Click for Drug Monograph
  is released because the hypothalamus is compressed
• Amenorrhea and galactorrhea in women and, less commonly, erectile dysfunction and gynecomastia in men if prolactin is overproduced
• Gigantism before puberty or acromegaly after puberty if growth hormone is overproduced
• Cushing's syndrome if ACTH is overproduced

Rarely, hemorrhage into a pituitary tumor causes pituitary apoplexy, with sudden headache, ophthalmoplegia, and visual loss.

Diagnosis

• MRI with 1-mm slices

Pituitary tumors are suspected in patients with unexplained headaches, characteristic visual abnormalities, or endocrinopathies. Neuroimaging with 1-mm thick slices is done. MRI is usually much more sensitive than CT, particularly for microadenomas.

Pituitary microadenoma

Treatment

Endocrinopathies are treated.

Pituitary tumors that produce ACTH, growth hormone, or thyroid-stimulating hormone are surgically excised, usually using a transsphenoidal approach. Sometimes, particularly for surgically inaccessible or multifocal tumors, radiation therapy is required.

Adenomas that produce prolactin are treated with dopaminergic agonists (eg, bromocriptineSome Trade Names
PARLODEL
Click for Drug Monograph
, pergolideSome Trade Names
PERMAX

, cabergolineSome Trade Names
DOSTINEX
Click for Drug Monograph
), which lower blood levels and often shrink the tumor. Surgery and radiation therapy are usually unnecessary.

Last full review/revision February 2008 by William R. Shapiro, MD

Content last modified February 2008