Galactorrhea is the spontaneous bilateral discharge of milky ﬂuid from the nipples. (Many women, especially those who have given birth, can express small amounts of milky ﬂuid from one or both nipples, and this is not considered abnormal.) Galactorrhea is uncommon but reports vary from 1% to 30%, depending on the population studied. Although not inherently dangerous, galactorrhea can be the harbinger of signiﬁcant underlying physiologic disruptions and, as such, deserves careful evaluation.
Because galactorrhea represents a
symptom, multiple causes can result in the same clinical presentation. Pituitary
adenoma or hypothyroidism can result in elevated prolactin levels, which can
stimulate the breast parenchyma and result in milk secretion. Galactorrhea can
also result as a side effect from pharmacologic agents. Most often this occurs
with those drugs that affect dopamine or serotonin production or metabolism.
(Some foods when consumed in excess can mimic this same process, notably
licorice.) Some autoimmune diseases (sarcoid, lupus) or Cushing disease may
result in the patient’s symptoms. Chronic chest wall irritation such as from
herpes zoster, breast stimulation, or breast irritation may result in the
activation of neural pathways normally associated with physiologic milk
production. Chronic stimulation of these neural pathways can result in
galactorrhea. Physiologic changes during pregnancy or after childbirth and/or
nursing may lead to persistent milk secretion. Most pathologic processes that
lead to galactorrhea result in an elevation of serum prolactin levels. This can
be helpful in evaluating the source and threat posed by these symptoms.
Galactorrhea is often accompanied by
other presenting complaints or conditions: one-third of patients with an
elevated prolactin level experience amenorrhea or infertility. Prolonged
hypogonadal amenorrhea resulting from hyperprolactinemia is associated with an
increased risk of osteoporosis, vaginal and genital atrophic changes,
dyspareunia, and libidinal dysfunction.
The evaluation of the patient with
galactorrhea will, in part, be dictated by any associated symptoms suggestive
of an underlying process. In the absence of other symptoms, measurement of
serum prolactin levels begins the evaluation process. (Pregnancy should always
be considered if menses are absent.) Prolactin should be measured in the
fasting, resting state because eating and stress can increase levels. An
elevated serum prolactin level suggest the need for radiologic evaluation of
the pituitary. The preferred approach is computed tomography or magnetic
resonance imaging of the sella turcica. Unfortunately, there is a poor
correlation between serum prolactin levels and the size of a pituitary lesion.
Testing of visual ﬁelds may be indicated if there is a pituitary macroadenoma (10
When prolactin levels are low and
imaging of the sella turcica is normal, observation alone may be sufﬁcient. If
observation is chosen, periodic reevaluation is required to check for the
emergence of slow-growing tumors. Treatment with bromocriptine is recommended
for patients who desire pregnancy, have distressing degrees of galactorrhea, or have macroadenomas.
Unfortunately, medical therapy may be associated with nausea, orthostatic
hypotension, drowsiness, or syncope, hypertension, or seizures, and
bromocriptine therapy may interact with phenothiazines or butyrophenones.
Medical therapy is generally
effective for patients with hyperprolactinemia. Prolactin levels should be
measured every 6 to 12 months and visual ﬁelds reassessed yearly. The pituitary
should be reevaluated every 2 to 5 years, based on the initial diagnosis. The patient’s symptoms may recur when medical
therapy is discontinued.
Rapidly growing tumors, tumors that
are large at the time of discovery, or those that do not respond to
bromocriptine therapy may require surgical or radiation therapy. Surgery can
often be accomplished via the transsphenoidal approach. Surgical therapy may
result in complete loss of pituitary function requiring careful replacement and
monitoring of other endocrine systems,
including the thyroid and adrenal.