Lactotroph adenomas (prolactinomas) are more amenable to pharmacologic treatment than any other kind of pituitary adenoma because of the availability of dopamine agonists, which usually decrease both the secretion and size of these tumors. For the minority of lactotroph adenomas that do not respond to dopamine agonists, other treatments must be used. Hyperprolactinemia due to other causes should also be treated if it causes hypogonadism.
This topic will review the major issues concerning the therapy of hyperprolactinemia due to lactotroph adenomas and other causes, with the exception of therapy during pregnancy, which is discussed separately. The causes, clinical manifestations, and diagnosis of hyperprolactinemia are also discussed elsewhere. (See "Management of lactotroph adenoma (prolactinoma) during pregnancy" and "Causes of hyperprolactinemia" and "Clinical manifestations and diagnosis of hyperprolactinemia".)
INDICATIONS FOR TREATMENT
There are two principal reasons why patients with hyperprolactinemia may need to be treated: existing or impending neurologic symptoms due to the size of a lactotroph adenoma, and hypogonadism or other symptoms due to hyperprolactinemia [1,2]. Our approach to management is similar to that suggested by the Endocrine Society Guidelines .
Adenoma size — A lactotroph adenoma 1 cm or more in size is a macroadenoma. Treatment is usually essential when the tumor is large enough to cause neurologic symptoms, such as visual impairment or headache. Treatment is usually desirable when the adenoma extends outside of the sella and abuts or elevates the optic chiasm, or invades the cavernous or sphenoid sinuses or the clivus; lesions of this size are likely to continue to grow and eventually cause neurologic symptoms.
The tumor is a microadenoma when it is less than 1 cm in diameter. Studies of the natural history of microadenomas show that 95 percent do not enlarge during four to six years of observation [3,4]. The 5 percent that do enlarge should be treated because of the increase in size alone.