Sunday, 10 May 2009

When three is a crowd….

I’ve often heard the term ‘a third nipple’ but I've never looked into it until today. Whilst preparing for a demonstrating session about mammary glands, I came across the term ‘polymastia’ and ‘polythelia’, otherwise known as an extra breast and an extra nipple, respectively. Immediately intrigued by this, I googled it and found images of these breasts and nipples. One particular case that caught my attention was a breast and nipple on the sole of a woman’s foot! A 22-year old woman sought medical attention for a lesion which she had on her left foot since birth (see picture below). The lesion was identified as a pseudomamma: incomplete breast tissue and a nipple. Further histological examination (examining tissue under a microscope) of the lesion confirmed the diagnosis as class 5 pseudomamma based on the Kajava classification system. The presence of fat, a nipple, an areola, and the absence of glandular tissue classified the lesion as a pseudomamma. This was the first known diagnosis of a pseudomamma on the sole of a foot. The patient eventually had the pseudomamma removed.
Pseudomamma on the foot

In further readings, I discovered that the phenomenon of extra breast tissue (either nipple or breast) was a lot more common than thought. Approximately 1-5% of the population present with this, although it occurs more commonly on the back, shoulders, face (yikes!) and thighs. Additionally, I discovered that extra breast tissue, when containing glandular tissue, is susceptible to diseases of normal breasts (cancer) and even monthly cyclical alterations of breasts induced by hormones ie. swelling, pain and sometimes even milk secretion. Fortunatley for the woman in this case, her pseudomamma was asymptomatic (ie. showing no symptoms). Imagine having to walk on a breast at certain times of the month. Ouch!

(1) Conde DM, Kashimoto E, Torresan RZ and Alvarenga M (2006) Pseudomamma on the foot: An unusual presentation of supernumerary breast tissue. Dermatology Journal Online. 12(4).
(3) Fleurs des Champs image: Wikimedia Commons

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