Serum prolactin levels in galactorrhea.

Some patients with galactorrhea will have normal serum prolactin levels but many will have elevated serum prolactin levels. The galactorrhea may be due to drug ingestion, nipple afferent nerve stimulation, nonneoplastic disease or injury, and intracranial tumors. Serum prolactin levels were measured by radioimmunoassay in 17 women with galactorrhea. Levels 5 and 6 times normal values were found in two women who had proved pituitary adenomas. The latter conditions must be strongly considered and functional tests may help in diagnosis prior to enlargement of a prolactin-secreting tumor to the size where changes in the sella are seen on x-ray or visual field changes occur. If galactorrhea persists when no evidence of tumor can be found, the patient must be periodically re-evaluated, as the tumor may have been too small for detection at the time of the previous examination.