The nipple – the signature of the breast

Prof Carol-Ann Benn discusses general nipple concerns from discharges to eczema.

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If the breast is to be considered an objects d’art, a mysterious beauty loved by many then surely the nipple is that part of the painting that draws one in, like the Mona Lisa smile.

This alluring body part glorified and glamified, sometimes enhanced and a product of many hetro male fantasies is the simplest of endocrine organs. It plays a role for many in nurture and the nipple with its multitude of sensory nerve endings is often pivotal for many in sexual play. But for all the mystique and excitement, it’s a rather simple organ.

Understanding the nipple 

The breast sits as a skin accessory, and doesn’t work like other endocrine organs, in that it has no negative feedback mechanisms. This means that if you stimulate it, it sends a message to the brain to produce more secretions. Unlike the thyroid and other endocrine organs which have complex mechanisms of recognising how they can increase the production of their end-product hormone. This is the secret to understanding nipple discharges and to successful breastfeeding as well.

The nipple is a glorified plug. Studies done on women (whether they’ve breastfed or not) have shown that if you stimulate the nipple and squeeze it, one can produce a discharge. Gentlemen, the nipple isn’t a radio control knob so unless with permission and a safe word, be gentle. Ladies don’t squeeze your nipples unless you want them to produce a secretion.

An important T&C is that any person (men have breasts) with any symptom should have a mammogram and ultrasound if over 40, and an ultrasound only if younger or if male. Men can produce a nipple discharge although they can’t breastfeed.

The best investigations to look at the ducts under the nipple is a high-resolution ultrasound. Often times people with nipple discharges may have a normal mammogram and ultrasound with the only findings being slightly dilated ducts. A sexy ultrasound technique is elastography which may be of value for small lesions in the ducts. There are between 35 and 50 ducts leading from the nipple and if you placed a small scope with an external diameter of only 1mm in a duct, you would need a 10 000-pixel resolution to see a small growth on the wall.

Different shapes and sizes

“Mine look different from hers.” Well darling, so does your hair and nose. Basically, the nipple sits in the centre of the areola, a slightly darker rim of also very specialised skin.

Nipples can be innies or outies and of different lengths and colours; some long, some short and stubby, some flat and some even inverted. The colours can vary from pink to brown as well as having some variegated colour.

Areolas are specialised skin that have small Montgomery follicles (small white bumps) on them; these are tiny secretory glands that lubricate the nipple. Areolas can also vary in colour and can darken with pigment during pregnancy. Some are well-defined, and some seem to fade in areas into the breast skin. And, yes some can have hair (it’s safe to pluck or laser).

Don’t squeeze the small white bumps. They will produce a white sebum which will refill and it’s possible to get an infection which can usually be treated with topical antibiotics.

Itchy nipple

Nipple itches, how awkward! Easier to discuss than other itches. Is it an itch on its own? When you look at your nipple, it looks normal. If it feels like you want to scratch inside your nipple (you can’t), this is sometimes a small mite, Demodex folliculorum, and can be seen on path biopsies of the nipple. A honey ointment, such as L-mesitran or a metronidazole ointment seems to help. 

Some ladies (who have prostheses in) complain of an itchy sensation inside the breasts. Not sure why this happens and sometimes when we take out these prostheses, they have almost a weep to the capsule.

The most common universal problem is dry skin. Alert here don’t use perfumed soaps on your nipples or your nether regions. Other causes of an itchy nipple are fungal infections (thrush), eczema and, more rarely, Paget’s disease can be mistaken as an itchy nipple.

Eczema is usually seen on both nipples (but may be on one) and can vary from dry flaky skin to a bleeding suppurating weepy wound. The secret to identifying the difference between eczema and Paget’s, is that eczema usually starts on the areola and not on the nipple, affecting the whole nipple and areola.

Eczema usually responds to a steroid cream, it should get better and not reoccur. If it reoccurs on a steroid, be sure that you see a specialist breast doctor so that Paget’s disease can be excluded.

Nipple discharges

Nipple discharges are classified according to colour and the number of ducts involved. Discharges from many ducts can be milky (physiological) which means a natural body function. The discharge of duct ectasia (inflammation of the ducts) can be green, yellow or even black and this is usually from more than one duct and has complex causes and is difficult to treat. The secret question to ask a woman is, is it spontaneous (leaks on its own) or non-spontaneous (leaks when you squeeze your nipples)? 

Spontaneous nipple discharge (Intraductal papillomas)

The discharge from a single duct that is spontaneous (occurs without squeezing) and is usually clear, yellow or blood-tinged is most likely from a ductal papilloma (benign tumour that grows in a milk duct). 

Papillomas may be single or multiple. Close to the nipple (usually single) or peripheral (can be single or multiple). Some can be seen on ultrasound and others are too small. An associated breast cancer may be detected by mammography and core needle biopsy in a small percentage of cases.

Intraductal papillomas that are multiple may be detected on ductogram (seldom used today as they don’t change management and are more like-old fashioned cartography maps giving direction but not detail). Today MRI scans are more like the Google maps that can sometimes be too detailed with TMI, making decisions complex. 

Currently, papillary lesions require the need for surgery post-core biopsy. A bit like polyps in the colon and atypical moles. There is only a 1 in 10 chance that they may be malignant and in select cases where a watch-and-wait is decided, close ultrasound follow-up is advised and are often not used in most centres. 

Fluid cytology on the leaking duct is also of no value as a negative cytology (no abnormal cells) shouldn’t prevent your specialist from doing a microdochectomy of the duct, if this is considered the right decision after a radiology and clinical review. 

Treatment 

The treatment is to excise the involved duct by a microdochectomy; the papilloma is sent for histology to confirm that it’s benign, as about 10% of duct papillomas may be ductal carcinomas or ductal carcinoma in situ.

Non-spontaneous discharge

Sometimes you may have squeezed as you saw small white flaky stuff on the top of the nipple. Please unlearn this bad habit.

Milky duct discharge from both breasts

The hormone that causes production of milk from the breast is prolactin. Prolactin can be manipulated by drugs, and salivary increase in prolactin can happen although it’s rare. Most importantly, when there is a nipple discharge exclude pregnancy.

Milky discharges (galactorrhoea) can be caused by a variety of hormonal imbalances, such as thyroid-, pituitary gland- or gynaecological problems. 

Rarely drugs that inhibit or deplete dopamine, such as certain psychiatric drugs (antidepressants in particular) and antihypertensives, can cause milk discharges.

In fact, even excessive stimulation of the breast mechanically can also cause lactation (may be seen in marathon runners or anyone that stimulates the nipple continuously). Stress can also cause a milky nipple discharge (due to the release of an acute stress hormone prolactin).

Working out the cause 

This should always involve a detailed history and physical examination followed by a pregnancy test. Blood tests should at least include a prolactin level and thyroid function test. The patient should be told to refrain from squeezing the nipple even if tingling and pressure is felt so as to allow the sebum plugs that normally block the ducts to reform. 

It’s seldom necessary to use Parlodel (drug to inhibit lactation).

Very rarely a pituitary adenoma (small hormone-producing benign tumour) is found in the pituitary gland in the head, and this can cause excessive production of prolactin. The assessment for this includes a brain MRI scan and the use of cabergoline.

Many ducts and many colours

A discharge can be a variety of colours from cheesy white to a green, yellow, black, brown or thick cheesy yellow discharge and commonly occurs when squeezing is duct ectasia. This is an inflammatory condition common in smokers and presents with burning shooting pain. Don’t squeeze.

Nipple discharge and an itchy nipple should always result in seeing a breast specialist. Of concern is a single duct discharge which is clear, blood-tinged or bloody especially if it’s spontaneous. This may require surgery and the minimum is to see a breast specialist. 

Header image by Adocbe Stock