Manuel A. Torres-Salichs MD,FACS Surgical Oncology, Breast Surgeon

Edileidis Tarrio, ARNP-BC, OCN





Nipple Discharge

The breast is a secretory gland that responds to the stimulation of different hormones, including estrogen and progesterone. These hormones are responsible for controlling breast development during puberty. Estrogen promotes the growth of the ducts in the breast, whereas progesterone helps in the development of the secretory cells. The functional unit of the breast is called the terminal duct lobular unit (TDLU). Mammary secretions originate from these breast lobules. It is important to differentiate between nipple discharge and secretion of the nipple.

Nipple discharge is defined as fluid that comes out spontaneously from the nipple.
Nipple secretion refers to fluid that is present in the breast and comes out upon mechanical stimulation of the nipple and underlying ducts.

The most common cause of bloody nipple discharge is a papilloma. This is a benign tumor. Treatment includes duct exploration and resection.

It is normal for many women to express fluid using external pressure. A small amount of sticky, gray, green, serous, or black viscous fluid could be present. The patient who is curious to check for discharge may cause continuous mechanical stimulation and as a consequence, have production of fluid. Women are advised to avoid checking themselves for discharge since benign discharge may resolve when the nipple is left alone. Nipple discharge is the third most common complaint among women after breast pain or a breast mass. Up to 50% of women in their reproductive years can express one or more drops of fluid from the breast. Nipple discharge is seldom caused by a malignancy. Nevertheless, it does raise the concern about two uncommon but serious conditions. These are breast cancer and a pituitary tumor.

Common Features:

• Unilateral or bilateral discharge
• Cycle variation
• Induced or spontaneous discharge
• Discharge may be clear, serous, milky, yellow, green, pink or slightly bloody, brown or black (old blood)
• Discharge may originate from one or multiple ducts

Normal/Benign Discharge:
During pregnancy and up to two years after delivery nipple discharge is normal and milky in nature. The same applies after a spontaneous abortion or an intentional termination of pregnancy in the second trimester.

Abnormal Discharge

Benign Ductal Conditions:

Intraductal Papilloma:
Intraductal papilloma is a benign (non cancerous) growth within the breast ducts. The presence of multiple papillomas is referred to as papillomatosis. This is the most common cause of nipple discharge. Papillomas usually affect women from 35- 50 years of age. The discharge fluid could be serous or bloody. The papilloma usually involves a single duct and is present in one breast. Although not considered a true precursor of cancer, women with papillomas may be at a slightly higher lifetime risk for carcinoma (5%). This is due to the possibility of the coexistence of other proliferative lesions.

Ductal Ectasia:
This is a condition characterized by the dilatation of major ducts and some degree of inflammation and fibrosis around the ducts. The cause is unknown, although breast feeding may be related. It is unknown whether the inflammatory process proceeds or follows the dilatation of the duct. Up to 60% of nipple discharges associated with ductal ectasia containing bacteria. Ductal ectasia does not indicate a predisposition to cancer.

Fibrocystic Breast Changes:
Fibrocystic changes may produce a serous or light green and often multiductal discharge. It is usually provoked rather than spontaneous.

Plasma Cell Mastitis:
It is a rare type of chronic mastitis usually found in multiparous women. It may lead to nipple inversion and may present with serosanguineous and thick nipple discharge.

Malignant Ductal Conditions:

Cancers infrequently present as an isolated discharge. The incidence of breast cancer associated to isolated nipple discharge ranges from .6% to 2%. The incidence goes up to 9% in patients older than 50 years of age. All types of breast carcinomas (e.g. ductal, lobular, tubular, and medullary) are sometimes diagnosed as a result of nipple discharge. Special attention should be given to papillary carcinoma, despite it being a rare malignancy (<1%). It is usually inside a duct and may present initially as unilateral nipple discharge that originates in one duct.

Endocrinologic Conditions:

All endocrinologic causes of nipple discharge have one common element. There is either a relative or absolute increase in prolactin. The breast responds appropriately and produces milk due to an abnormal signal (high prolactin levels). This is a hormone produced in the anterior pituitary gland. It causes the production of milk in pregnant women after delivery. Galactorrhea is defined as milk production in a woman who is not pregnant or is more than 2 years from the last breastfeeding. The nipple discharge has the appearance of milk, occurs from multiple ducts, is usually spontaneous rather than provoked, and is most commonly bilateral.

Conditions that can cause an increased in prolactin production include:


  • Physical and emotional stress
  • Sleep
  • Exercise
  • Eating (especially midday high-protein meal)
  • Excessive breast stimulation
  • Pregnancy/ nursing


  Hormonal medications
  Antidepressants and anxiolytics
  H2 receptor antagonists, including cimetidine and ranitidine
  Others, amphetamines, anesthetics, arginine, cannabis, danazol isoniazid, metoclopramide, opiates and valproic acid

Medical and Surgical Conditions:

  • Pituitary adenoma
  • Growth hormone producing tumors
  • Hypothyroidsm
  • Chronic renal failure
  • Previous thoracotomy
  • Thoracic tumors
  • Herpes zoster
  • Hypernephroma
  • Bronchogenic carcinoma


The appropriate treatment should be based on the specific condition causing the abnormal nipple discharge. The surgical treatment of spontaneous nipple discharge includes central duct exploration and excision. A patient with nipple discharge should undergo evaluation by a breast specialist.