What is Galactorrhea?
Galactorrhea refers to the production of milk from the breast that is not linked to pregnancy or breastfeeding. If a woman produces milk a year after she has stopped breastfeeding, this is classed as non-lactational, and is known as galactorrhea. This condition can be influenced by various hormones such as prolactin, estrogens, and thyrotropin-releasing hormone (TRH), which all have the ability to impact the production of milk.
What Causes Galactorrhea?
Galactorrhea, the term for excessive or inappropriate production of breast milk, can be caused by various factors that mainly originate from two areas – the hypothalamus and the pituitary gland (in the brain), or by causes not related to these structures.
When it comes to hypothalamus-pituitary causes, the first common cause is tumors that secrete a hormone called prolactin or ‘Prolactinomas’. These are the most common hormone-releasing tumors found in the pituitary gland. If these tumors are smaller than 1 cm, they are called microprolactinomas. If larger than 1 cm, they are known as macroprolactinomas. The prolactin levels in the blood usually correlate with the size of the tumor.
Other types of non-prolactin-secreting pituitary tumors and disorders affecting the pituitary stalk (the part that connects the hypothalamus and the pituitary gland) or hypothalamus can also cause galactorrhea. They cause a higher level of prolactin (hyperprolactinemia) by interfering with the normal flow of a chemical called dopamine from the hypothalamus to the front part of the pituitary gland, resulting in increased prolactin production, typically less than 200 ng/ml.
Non-hypothalamus-pituitary causes include thyroid underfunction or hypothyroidism. This condition can cause an increase in a chemical called TRH , which can stimulate specific cells, causing hyperprolactinemia and galactorrhea.
Additionally, some medications can cause elevated prolactin levels leading to galactorrhea. These include certain antipsychotics, antiemetics (used for vomiting), antidepressants, opioids, and a blood pressure medicine called verapamil. These drugs work by interfering with dopamine’s role in the body, leading to reduced dopamine output, and hence increased prolactin levels.
Other causes include kidney failure, which can result in the body’s inability to clear prolactin properly, thereby leading to increased prolactin levels. Burns, surgeries, or herpes zoster infections on the chest can also result in higher prolactin levels, possibly because the pain signals interfere with dopamine release. Furthermore, sometimes, hyperprolactinemia occurs without a known cause, which might be due to small undetected microprolactinomas. In such cases, the condition either resolves on its own in about a third of patients or might remain stable in half of the patients.
Risk Factors and Frequency for Galactorrhea
Hyperprolactinemia is a condition that is more prevalent in women. In the general adult population, only 0.4% may experience it, but this rate jumps drastically when looking at women with reproductive problems, anywhere from 9 to 17%. Notably, women who have polycystic ovary syndrome also see a high rate of hyperprolactinemia, with 17% affected.
Signs and Symptoms of Galactorrhea
When evaluating symptoms linked to high levels of prolactin in the blood, a range of factors needs to be considered. These include changes in menstrual cycles, lowered sex drive, milky discharge from the breasts (galactorrhea), problems with erections, difficulties in getting pregnant, and the development of breasts in men (gynecomastia). A medication history needs to be taken into account to understand if certain drugs may be causing these symptoms. If a growth in the pituitary gland is suspected, additional checks for headaches and vision problems should be carried out.
For a physical examination of galactorrhea, the patient must be positioned sitting and leaning forward. Gentle pressure should be applied to the colored part of the breast (areola), towards the direction of the nipple. This milky discharge can usually be seen in both breasts and can be white or green in color. If there’s a bloody discharge, it could be a sign of breast tumors and would require further investigation. Using a Sudan IV stain can help identify if the discharge is milk by detecting the presence of fat droplets.
Testing for Galactorrhea
When evaluating a condition called hyperprolactinemia (high levels of a hormone called prolactin in your blood), your doctor will likely need to take a sample of your blood to measure the levels of prolactin. The test they use is called a sandwich ELISA assay; it’s like a tag team match where one molecule of prolactin needs to bind to two antibodies (proteins that identify and neutralize foreign objects) to be measured.
However, in very rare cases, if someone has a large tumor in the pituitary gland (a small bean-sized gland at the base of your brain) and super high levels of prolactin, there’s a peculiar thing that can happen during testing. This is called the “hook effect.” Because there’s so much prolactin in the sample, not enough of it is binding effectively to both antibodies in the test. To overcome this, your doctor might dilute the sample to get a more accurate reading, revealing the extremely high levels. This “hook effect” should be kept in mind if you’re diagnosed with a big pituitary tumor, particularly if you’re experiencing signs like breast discharge and disturbances in your periods while also showing only slightly higher prolactin levels than normal.
In addition, other hormones produced by the pituitary gland may need to be assessed, based on your symptoms and general health. A scan of your brain (more specifically, an MRI of the pituitary gland) may also be carried out to check for possible lesions or abnormalities causing high prolactin levels. If the tumor is located near an area which heavily influences sight (optic chiasma), it’s important to have your vision assessed to ensure it hasn’t been affected.
Treatment Options for Galactorrhea
If breast-related health issues have been ruled out, the focus of treatment shifts towards managing high levels of the hormone prolactin (hyperprolactinemia). Hyperprolactinemia is addressed if there is a problem with the pituitary (a small gland at the base of the brain), or if menstrual problems and excessive milk production (galactorrhea) are causing issues. If these issues are not causing significant problems, medical professionals may choose to carefully watch the condition without active treatment.
Bromocriptine or cabergoline are the two main medicines used to treat hyperprolactinemia. Both are classified as dopamine agonists, which means they work by activating specific dopamine receptors called D2 receptors in the brain and reduce the production of prolactin. They are effective at bringing prolactin levels back to normal and reducing the size of any pituitary tumors. However, like all medications, there are some side effects. These can include nausea, vomiting, low blood pressure when standing (orthostatic hypotension), daytime sleepiness, and headaches. It has been reported that high doses of cabergoline can cause heart valve issues, hence patients taking a high dose are advised to have a heart scan (echocardiogram) every year.
If hyperprolactinemia is caused by certain medicines, the problematic medicine should be stopped or changed. However, using dopamine agonists in these instances may slightly increase the risk of making underlying mental health conditions worse.
Occasionally, galactorrhea can happen even when prolactin levels are normal, a condition known as normoprolactinemic galactorrhea. If it causes significant problems, such as troublesome galactorrhea or menstrual cycle irregularities, dopamine agonists can be used to provide symptom relief. Once the symptoms have subsided, the treatment can be gradually reduced and stopped.
What else can Galactorrhea be?
There are various conditions that might occur, which include:
- Acromegaly (abnormal growth of the hands, feet, and face)
- Reaction from breast stimulation
- Bronchogenic carcinoma (a type of lung cancer)
- Burns
- Effects from breast surgery
- Craniopharyngioma (a type of brain tumor)
- Cushing’s disease (overproduction of a hormone called cortisol)
- Irritation of the chest wall
- Hypothyroidism (underactive thyroid)
- Conditions with unknown causes (idiopathic)
- Lymphoma (a type of blood cancer)
- Molar pregnancy (a non-viable pregnancy)
- Side effects from medication and herbs
- Pituitary adenomas (tumors in the pituitary gland)
- Renal failure (kidney failure)
- Sarcoidosis (inflammation that produces tiny lumps of cells in various organs)
- Tuberculosis (infection that primarily affects the lungs)