Nipple Discharge and Mastitis in a Non-Lactating Woman
Essentials
Rule out a tumour of the breast by sufficient investigations in all cases with serous unilateral discharge or bloody discharge. The risk of a malignant process increases with age: in a person less than 40 years of age the risk is 3%, and 30% in a person over 60 years of age.
Milky (greenish, brownish, or yellow) discharge or discharge from more than one mammary duct or from both breasts does not suggest breast cancer.
Mastitis in a non-lactating woman is treated with the same principles as in a lactating woman Lactational Mastitis but mammography should be performed after the treatment.
Examine by palpation and squeezing whether the discharge is unilateral or bilateral. This is particularly important if the patient reports that the discharge is unilateral.
The investigations for bloody discharge or unilateral serous discharge include:
palpation of the breasts (looking for nodules and the orifice of the duct where the discharge comes from)
mammography, ultrasonography and ductography.
Galactorrhoea
Investigations
Palpation of the breasts
Serum prolactin and TSH in an adult woman
Mammography and/or ultrasonography if considered necessary
Prolactin is the principal hormone regulating the milk production.
Secreted by the anterior pituitary gland and in small amounts also by placental, decidual and endometrial tissues
Secretion peaks during sleep.
One single laboratory determination is not always reliable because e.g squeezing or touching the breasts, intercourse, and stress may temporarily increase the prolactin concentration.
Any factor that inhibits dopamine action causes hyperprolactinaemia and galactorrhoea.
Several drugs may cause galactorrhoea.
Phenothiazines and other neuroleptic agents
Tricyclic antidepressants
Opioids
Oral contraceptives
Oestrogen and antioestrogen products
Metoclopramide
Verapamil
Isoniazid
Antihistamines
Hyperprolactinaemia is caused by thyroid-related hypothyroidism (high serum TSH and low serum free thyroxine) in about 10% of the patients.
Treatment with thyroxine will also correct hyperprolactinaemia.
If thyroxine treatment does not correct the hyperprolactinaemia or there is discrepancy in the thyroid function tests, probable cause is a prolactin-secreting adenoma in the pituitary gland. In this case, prolactin concentrations are remarkably high (over 1 000 mU/l).
Investigations take place in a hospital setting.
One fourth of patients with chronic renal failure have galactorrhoea.
Bilateral galactorrhoea in an adult woman with normal laboratory results, normal menstrual cycle, and no abnormal clinical signs can be followed up for one year in primary care. If the discharge continues, the patient should be referred to a specialist for further pituitary function tests. For the investigations of amenorrhoea see Amenorrhoea.
Sometimes milk secretion persists even if breastfeeding has ended.
If necessary, milk secretion after delivery may be stopped with a single 1-mg dose of cabergoline. The drug may lower the blood pressure for 3-4 days.
If hyperprolactinaemia is associated with the use of psychiatric medication, a change of the drug may be tried. Medication to suppress milk secretion is not indicated.
In the newborn a milky discharge up to the age of a few weeks is a normal phenomenon that does not require investigations.
Milky discharge in men, children, or adolescents is always an indication for specialist consultation.
Bloody or clear discharge
Bloody discharge from the breasts without an underlying abnormality may occur during pregnancy or soon thereafter.
The most common cause of discharge from the breast is intraductal papilloma (about 40%).
The change is often non-palpable and may be diagnosed only by galactography.
Ultrasonography may sometimes reveal an enlarged ductal area.
Solitary papillomas are usually benign, but in the case of multiple papillomas, i.e. papillomatosis, cancer is detected in up to one third of the patients.
A sample of the discharge for cytological examination may be taken but its sensitivity is only about 30-40%.
Mammography complemented with ultrasonography is used to exclude other changes.
Mastitis in a non-lactating woman
Periductal mastitis is the most common form of mastitis in non-lactating women; the patient is typically a smoker.
Pain and purulent periareolar discharge are the most common symptoms.
Clinical findings include inflammation, abscess, lump or fistula around the areola, or an inverted nipple.
Usually it is a mixed infection caused by several both aerobic and anaerobic bacteria; choose an antimicrobial drug effective against staphylococci.
Abscess formation may be associated with the infection, always requiring drainage.
If the infections are recurrent or become chronic, even extensive surgical interventions may be required, e.g. mamillary surgery where the diseased ductal area is excised up to the tip of the mamilla. The operation can be performed under local anaesthesia in an outpatient unit.
Mammography must always be performed after treatment to diagnose possible carcinoma.
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Paepke S, Metz S, Brea Salvago A et al. Benign Breast Tumours - Diagnosis and Management. Breast Care (Basel) 2018;13(6):403-412. [PubMed]