No. The pituitary is a small endocrine gland located at the base of the brain that controls other endocrine glands - including the thyroid, the adrenals, the ovaries and testes. It also secretes the hormone that regulates growth and metabolism, as well as prolactin, the hormone that stimulates production of breast milk. The vast majority of pituitary tumors are benign, but some can be very troublesome and even life-threatening if they grow large and press on the optic nerve, surrounding brain structures, or the pituitary itself, limiting its production of hormones.
There are two types of pituitary tumors - those that secrete hormones and those that don't. For example, a tumor arising from the cells of the pituitary that produce prolactin will also secrete prolactin. This is the most common type of pituitary tumor and usually is treatable by surgery. The high prolactin levels it secretes suppress production of luteinizing hormone and follicle stimulating hormone, the pituitary hormones that stimulate production of estrogen or testosterone. Men with these tumors have low testosterone levels and lose their sex drive and eventually their masculine characteristics. Women with prolactin-producing tumors often do not ovulate, experience low estrogen levels, and cease having menstrual periods. Both men and women with low levels of sex hormones develop osteoporosis.
Pituitary tumors that don't secrete hormones may not be found until they get large enough to press on the optic nerves and affect vision.
Pituitary tumors are treated with surgery to remove them, radiation therapy to kill the tumor cells, or drugs to shrink the tumor or interfere with excess hormone production. It is best to have treatment at a hospital with a neuroendocrine or pituitary unit. If you need surgery for a pituitary tumor, make sure that your neurosurgeon specializes in pituitary surgery. These operations are almost always successful when performed by a skilled and experienced practitioner.
Andrew Weil, M.D.