(See also Pituitary Lesions Pituitary Lesions Patients with hypothalamic-pituitary lesions generally present with some combination of Symptoms and signs of a mass lesion: headaches, altered appetite, thirst, visual field defects—particularly... read more .)
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 adrenocorticotropic hormone (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 of Pituitary Tumors
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 figure Higher visual pathways—lesion sites and corresponding visual field defects Higher visual pathways—lesion sites and corresponding visual field defects ).
Many patients present with an endocrinopathy due to hormone deficiency or excess:
Diabetes insipidus Central Diabetes Insipidus Diabetes insipidus results from a deficiency of vasopressin (antidiuretic hormone [ADH]) due to a hypothalamic-pituitary disorder (central diabetes insipidus) or from resistance of the kidneys... read more if less vasopressin is released because the hypothalamus is compressed
Amenorrhea Amenorrhea Amenorrhea (the absence of menstruation) can be primary or secondary. Primary amenorrhea is failure of menses to occur by age 15 years in patients with normal growth and secondary sexual characteristics... read more and galactorrhea Galactorrhea Galactorrhea is lactation in any men or in women who are not breastfeeding. It is generally due to a prolactin-secreting pituitary adenoma. Diagnosis is by measurement of prolactin levels and... read more in women and, less commonly, erectile dysfunction Erectile Dysfunction Erectile dysfunction is the inability to attain or sustain an erection satisfactory for sexual intercourse. Most erectile dysfunction is related to vascular, neurologic, psychologic, and hormonal... read more and gynecomastia Gynecomastia This photo shows enlarged breast tissue in a male patient. Gynecomastia is hypertrophy of breast glandular tissue in males. It must be differentiated from pseudogynecomastia, which is increased... read more in men if prolactin is overproduced
Gigantism Gigantism and Acromegaly Gigantism and acromegaly are syndromes of excessive secretion of growth hormone (hypersomatotropism) that are nearly always due to a pituitary adenoma. Before closure of the epiphyses, the result... read more before puberty or acromegaly Gigantism and Acromegaly Gigantism and acromegaly are syndromes of excessive secretion of growth hormone (hypersomatotropism) that are nearly always due to a pituitary adenoma. Before closure of the epiphyses, the result... read more after puberty if growth hormone is overproduced
Sometimes pituitary tumors that compress tissue throughout the anterior lobe of the pituitary reduce production of multiple pituitary hormones, causing generalized hypopituitarism Generalized Hypopituitarism Generalized hypopituitarism refers to endocrine deficiency syndromes due to partial or complete loss of anterior lobe pituitary function. Various clinical features occur depending on the specific... read more .
Rarely, hemorrhage into a pituitary tumor causes pituitary apoplexy, with sudden headache, ophthalmoplegia, and visual loss.
Diagnosis of Pituitary Tumors
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.
Treatment of Pituitary Tumors
Surgical excision when possible
For endocrinopathies, drug 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, bromocriptine, pergolide, cabergoline), which lower blood levels and often shrink the tumor. Surgery and radiation therapy are usually unnecessary.
Most pituitary tumors are adenomas, which may be secretory or nonsecretory.
Secretory adenomas may cause diabetes insipidus, galactorrhea, Cushing syndrome, or gigantism or acromegaly.
Any pituitary tumor may compress optic nerve tracts, causing bitemporal hemianopia, unilateral optic atrophy, or contralateral hemianopia, or it may compress pituitary tissue, causing a deficiency of pituitary hormones.
Excise tumors and treat endocrinopathies; adenomas that produce prolactin may require only treatment with dopaminergic agonists.