What is a pituitary adenoma?
are benign tumors that arise from the pituitary gland. Pituitary tumors are rarely malignant. They are common tumors that arise from the pituitary gland located at the base of the brain. If they grow large enough, they can compress the optic nerves causing serious vision problems. Small pituitary tumors are known as microadenomas. Larger pituitary tumors are called macroadenomas. Some pituitary tumors produce excessive amounts of hormones that can disrupt the body’s metabolism. The most common type of hormonally active pituitary tumor is the prolactinoma. Excess prolactin in the blood may lead to irregular or absent menstrual periods in women (amenorrhea), decreased libido (sex drive) and erectile dysfunction (ED) in men. In addition, prolactinomas can cause infertility or inappropriate milk production by the breast in both men and women. A number of medicines are available to treat this disorder so that surgery is needed only infrequently. Most patients with prolactinomas are treated
A pituitary adenoma is a tumor-that is, a growth of tissue in which cells multiply in an uncontrolled manner. Adenomas are located just next to, or within the pituitary gland. The adenoma can be much smaller than the gland when the symptoms it causes become noticeable and the adenoma is diagnosed. Most pituitary adenomas are ‘microadenomas’, which measure 3 to 9 mm (1/8 to 3/8 of an inch) in diameter, although a few patients have ‘macroadenomas’, which are 10 mm or larger in diameter. Macroadenomas often cause problems with normal pituitary function because of compression of the gland or vision problems from compression of the optic nerves. Almost all adenomas are benign, rather than malignant, which means that they are relatively slow-growing and are slow to invade surrounding tissues. They very rarely metastasize or spread to other areas of the body.
Pituitary adenoma is the medical term for a tumor of the pituitary gland. The word adenoma specifically means tumor of glandular tissue. Pituitary adenomas are quite common in the general population. It is estimated that around 20% of all individuals will develop a pituitary tumor at some point during their lifetime, though many do not cause any problems and are never diagnosed. Most pituitary tumors are not capable of metastasis (spreading to distant sites throughout the body) and are therefore referred to as benign. Two-thirds of pituitary adenomas will remain completely confined to the pituitary gland. Approximately one-third will expand into tissues that are in the immediate vicinity of the pituitary gland, such as the brain. Less than one percent of all pituitary adenomas are able to metastasize throughout the body and are referred to as malignant. Pituitary tumors occur in every age group but are rarely diagnosed before age twenty.
The pituitary is the master control center of hormones in the body. It sits in a crevice called the sella turcica at the base of the skull. This location puts it right under the optic chiasm, which is the crossing point of the two vision nerves (optic nerves). The normal pituitary gland produces several important hormones: adenocorticotrophic hormone (ACTH) stimulates the adrenal gland; thyroid stimulating hormone (TSH) stimulates the thyroid gland; luteinizing hormone and follicle stimulating hormone (LH and FSH) interact with the sexual organs; growth hormone (GH) is involved with sugar metabolism and cell growth; and prolactin (PRL) affects lactation. Pituitary adenomas are slow growing, benign tumors of the pituitary gland. They represent 10-15% of all brain tumors. Those that are small (less than 1 cm in largest diameter) are called microadenomas, while larger tumors (greater than 1 cm) are commonly called macroadenomas. Pituitary tumors can also be divided into functioning and no
