Nipple discharge is a common symptom of breast disease and can be divided into physiologic and pathologic discharge. Physiological discharge refers to lactation during pregnancy and lactation, bilateral nipple discharge caused by oral contraceptives or sedative drugs, and unilateral or bilateral small amount of discharge in postmenopausal women. Pathological overflow refers to natural overflow from one or more ducts on one or both sides that is not related to pregnancy and lactation under non-physiological conditions. Intermittent and persistent nipple overflow from months to years mainly refers to pathological overflow.
I. Causes of morbidity
1. Classification.
There are two types of nipple overflow: true overflow and pseudo-overflow. True overflow refers to the natural overflow of the nipple during non-pregnancy and non-lactation, while pseudo-overflow refers to the leakage of superficial nipple erosion or breast fistula.
2, Etiology.
The etiology of true nipple overflow can be caused by hemophilia, purpura, endocrine disorders, ductal lesions itself and intra-mammary lesions. Such as intraductal papilloma, cystic hyperplasia of the breast, ductal dilatation of the breast, ductitis of the breast, intraductal carcinoma of the breast, etc., are common causes of nipple overflow.
II. Pathogenesis
Nipple overflow is an abnormal secretion of fluid of different nature discharged from the breast ducts.
The basic pathological changes that cause nipple overflow are the invasion of the large duct system of the breast by different lesions, resulting in inflammation, erosion, bleeding and other phenomena, or the invasion of the large duct by malignant tumors that produce the above pathological changes.
1.Clinical typing.
(1) According to the pathogenesis, true papillary overflow is divided into 2 types.
Intraductal type.
This includes neoplasms originating from the epithelium of the breast ducts, ductal papilloma, ductal dilatation, cystic proliferative disease, etc.
Extraductal type.
This includes lesions outside the ducts such as purulent inflammation, tuberculosis, and tumors of the breast that involve or invade the ducts and cause secretions to overflow from the nipples.
(2) Nipple overflow is often unilateral and can occur on both sides at the same time. The milk ducts may be single or multiple. According to the overflowing milk ducts, they can be divided into the following two types.
Unilateral single duct nipple overflow.
It is common in intraductal papilloma, and unilateral multiductal overflow is common in ductal dilatation and cystic hyperplasia of the breast;
Bilateral polypoidal overflow.
Most often seen in endocrine disorders, drug reactions, amenorrhea-overflow syndrome or certain benign breast diseases.
2, the nature of nipple overflow: the site and nature of nipple overflow has important clinical significance in inferring the nature of the disease. According to the nature of the nipple overflow can be divided into the following 7 categories.
(1) Milk-like fluid.
The color of the overflow resembles defatted milk. It is commonly seen in amenorrhea-overflow syndrome (lactorrhea), anterior pituitary hyperfunction syndrome, or after taking oral contraceptives.
It is caused by the pituitary gland being inhibited from releasing too much prolactin, and can also occur in some patients with mastocytosis, when there is often multiple ductal overflows on both sides and automatic outflow.
(2) Pimple-like overflow.
Mostly caused by ductal dilatation of the breast, the patient mostly has congenital nipple indentation and overflow of lipid pimple-like secretions with a foul odor from the nipples.
This type of overflow is viscous, mixed with multiple colors, and spontaneously overflows. It is also usually bilateral and multitubular. Patients often have burning, swelling and itching, and it is also seen in menopausal or young and middle-aged women with hypogonadism.
(3) Watery fluid.
The overflow is thin and watery, mostly caused by diseases such as intraductal papilloma, cystic hyperplasia of the breast and breast cancer.
(4) Purulent fluid.
The overflow resembles pus and is commonly seen in postpartum acute mastitis and breast abscesses.
(5) Plasmatic fluid.
Light yellow in color, caused by intraductal papilloma in the lower part of the nipple in most cases, also seen in cystic hyperplasia of the breast, ductal dilatation of the breast and breast cancer.
(6) Hematochezia or plasma hematochezia.
Bloody fluid is red in color, plasma bloody is pink in color. Bloody fluid is more common with intraductal papilloma. If a patient over 50 years old has unilateral bloody nipple overflow, it often suggests that it may be intraductal papillary carcinoma and should be given high priority. Plasma hematochezia can be caused by either intraductal papilloma, cystic hyperplasia of the breast or intraductal papillary carcinoma.
(7) Pale green overflow.
The secretion is a lighter, paler green fluid, which is less common. It is commonly seen in cystic hyperplasia of the breast.