Polymastia: The rare phenomenon where women produce milk in their armpit

After giving birth to triplets, a mother discovered that she is producing breast milk in her armpit. This little-known phenomenon, which affects about 6% of women, is known as polymastia.

Mum of three lactates from her armpits

Linda Jones, a 39-year-old mum, noticed that her armpits were 'hard as a rock and swollen' days after she gave birth to triplets. After examining the area, she discovered a lump under her armpit, and much to her astonishment, it was actually full of breastmilk!

The mum caused quite a stir when she posted the video on TikTok, where she has been sharing her pregnancy journey. The video has amassed over a million views and comments of disbelief.

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What is polymastia?

This phenomenon, as strange as it sounds, is not that uncommon. It's called polymastia. Polymastia is the presence of extra breast tissue in the body, and it affects about 6% of women, according to a paper published in 1999 in the journal Mayo Clinic Proceedings. The extra breast tissue can include a nipple or not, and can thus lactate.

So, how does a breast form under one's armpit? During fetal development, mammary glands form along the mammary ridge, which runs from the side of the body from the armpit to the groin. Usually, the ridges disappear all throughout the body, except for the breasts. But in some cases, they don't fully disappear.

Women who have extra breast tissue may not even be aware of it until they give birth and start to lactate. While the condition is mostly harmless, the extra breast tissue is also prone to developing begnin and malignant breast cancer cells. It is important to tell your health professional about your condition and get checked for lumps in the specific area.

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