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Galactorrhea with normal prolactin
This week I saw two young women, a 31-year-old and a 21-year-old with galactorrhea. They were sent to me from two different gynecologist’s offices. Both had analysis of the breast discharge which confirmed breast milk. Both had normal prolactin on repeat testing. One had pituitary MRI which showed “physiologic hypertrophy” but no pituitary adenoma. The other was to have an MRI but was sent to me first.
Not all elevations of prolactin are due to prolactinoma. Not every case of galactorrhea is associated with high-serum prolactin. In cases such as these, it is essential to take a thorough history.
Many medications have been implicated in hyperprolactinemia and galactorrhea. The most classic are the antipsychotics. Other psychotropic medications including selective serotonin reuptake inhibitors, and tricyclic antidepressants can cause galactorrhea as well. Metoclopramide and H2 blockers such as cimetidine can cause galactorrhea. There have been reports associated with antihypertensive medications including methyldopa, reserpine, atenolol and verapamil. Galactorrhea can also occur due to the herb fenugreek and illicit drugs such as amphetamine and marijuana. Both patients denied taking any medications or drugs.
Other medical disorders must be screened for. The most common is untreated hypothyroidism. Elevated levels of thyrotropin-releasing hormone stimulate pituitary lactotrophs. With therapy, breast milk production ceases. Chronic renal failure can cause elevated prolactin and galactorrhea due to decreased renal excretion of prolactin. Both women had normal thyroid-stimulating hormone and no other medical diagnoses.
Chest wall trauma or irritation can cause galactorrhea with or without hyperprolactinemia. I have seen two cases. One was due to steering wheel injury to the breasts during a motor vehicle accident. The other was due to an injury to the chest acquired while playing softball. Other causes of galactorrhea include tight-fitting clothing, surgery to the breast or chest wall, herpes zoster and burns. Both patients did not have such history.
However, these women were both new mothers. One had a 13-month-old and had never breast fed. The other had an 18-month-old and stopped nursing about 8 months ago. I reassured both of them that they had benign physiologic galactorrhea. Women may lactate for as long as two years after cessation of breast feeding. I encouraged them to avoid nipple stimulation. With time and patience, breast milk production should stop.
