Nipple Discharges

The second main presentation of breast problems is a nipple discharge.Nipple discharges are classified according to colour and the number of ducts involved. Discharges from many ducts can be milky (physiological). The discharge of duct ectasia can be green, yellow or even black and this is usually from more than one duct.

Single Duct Discharge

The important question to ask when a lady presents with a nipple discharge is did you see it on your clothes or did you squeeze.

The discharge from a single duct that is spontaneous (occurs without squeezing) is usually clear yellow or blood tinged and this is most likely from a duct papilloma.

Milky multiple duct discharge.
This may or may not be unilateral or bilateral. Pregnancy should first be excluded. Milky discharges (galactorrhoea) can be caused by a variety of hormonal imbalances such as thyroid problems, pituitary gland problems or gynaecological problems. Rarely drugs that inhibitor deplete dopamine such as certain psychiatric drugs (antidepressants in particular) and antihypertensives, can cause galactorrhoea. In fact, even excessive stimulation of the breast mechanically can also cause lactation (this may be seen in marathon runners).

Stress can also cause a milky nipple discharge (due to the release of an acute stress hormone prolactin). Management should entail and detailed history and physical examination followed by a pregnancy test (if indicated), and prolactin level and thyroid function tests. 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 is seldom necessary to use parlodel, a drug that inhibits lactation.

Of concern is a single duct discharge that is clear, blood tinged or bloody especially if it is spontaneous. 

Intraduct Papilloma
This presents with a bloody nipple discharge, which can be localised to one duct.  By “milking” the skin over the duct towards the nipple, blood or clear yellow fluid will ooze out of the relevant nipple orifice.  An associated breast cancer may be detected by mammography. Intraduct papillomas may be multiple and may be detected on ductogram.

The treatment is to excise the involved duct by a micro-dochectomy; the papilloma is sent for histology to confirm that it is benign, as a percentage of duct papillomas may be ductal carcinomas or ductal carcinoma in situ.

Duct Ectasia (Obstructive Mastopathy)
This also occurs in the twenty-five to fifty-year old female and is on the increase. Duct ectasia is a complex disorder where there seems to be a sebaceous like thick breast secretion (like porridge or toothpaste) that blocks the ducts (causing ectasia or dilatation of the ducts). It also leaks into the breast stromal fat (periductal mastitis) causing inflammation.  This periductal mastitis is a chemical inflammation, followed by a secondary bacterial infection.Smoking seems to predispose to sqamous metaplasia which presents like duct ectasia. It is a condition caused by a combination of environmental factors, hormonal interaction and stress.

A patient with duct ectasia may present with:

	Nipple discharge usually when the nipple is squeezed (a pus swab must be taken of the nipple secretion for culture).
	Nipple retraction or horizontal fissuring of the nipple.
	Mastalgia (breast pain which is usually described as a burning or shooting pain) due to a plasma cell mastitis (inflammation of the breast caused by the thick toothpaste-like material extruding out of the duct lumen becoming infected with anaerobic bacteria).
	Non-lactating breast abscess (progression from the plasma cell mastitis to bacterial infection and abscess formation).
	Mammillary duct fistula (communication between the major ducts and the preriareolar skin, at the point where the non-lactating breast abscess ruptures outwards, to drain either spontaneously or where the doctor lances the pus).

Treatment consists of giving antibiotics specific for the bacteria cultured (commonly a staphylococcus aureus), such as Augmentin or Bactrim.  Non-lactating breast abscess may require drainage but should initially be treated with ultrasound guided aspiration. If the condition pursues a chronic relentless course, the major breast ducts must be excised surgically (macrodochectomy/cone excision) via a subareolar incision. This procedure should involve significant counselling of the patient as a percentage of patients may develop complications from this procedure (recurrent fistulae, loss of the nipple areolar complex).

The treatment for duct ectasia is thus antibiotics except when it is intractable or complicated (such as when there are recurrent discharges or there is a non response to antibiotics). Topical Bactroban ointment twice a week is useful for maintenance.