Free Shipping on All Orders $75 Or More!

Your Trusted Brand for Over 35 Years

Health Protocols

Fibrocystic Breast Changes


Structure and Function of the Breast

Structure and Function of the Breast

Breast tissue is composed of ducts, lobules, ligaments, connective tissue, blood and lymphatic vessels, lymph nodes, nerves, and fat (Mayo Clinic 2015a). Each female breast contains 10–15 ducts that begin within the breast and merge at the nipple. It is through these ducts that milk passes during lactation. For each duct, there is a lobule surrounded by fat cells. The lobule is the milk-producing structure in the breast (Johns Hopkins Medicine 2012; Neville 2014). The breast is supported by ligaments and bands of fibrous tissue that together determine the breast's shape and position (Prendergast 2013).

Breast lobules and ducts react to hormones to produce milk during lactation. The pituitary gland at the base of the brain releases prolactin and oxytocin, which stimulate milk production and release (Nussey 2001). However, breast tissue is also responsive to estrogen and progesterone (Mauvais-Jarvis 1986). All four of these hormones are important for the appropriate timing of lactation, suppressing ovulation during lactation, milk production and expression, and growth and maturation of breasts during development (Clevenger 1997; Jonas 2009; Bellmann 1976; Neville 2009).

Types of Fibrocystic Breast Abnormalities

Benign breast conditions are divided into three categories based on how the tissue extracted during a biopsy looks under a microscope (ie, histologically) (Dupont 1985; Tamimi 2010; Mayo Clinic 2013b; ACS 2015). The categories are:

  • Non-proliferative (no increase in cell number or growth)
  • Proliferative without atypia (overgrowth of normal-appearing cells lining breast lobules and ducts)
  • Atypical hyperplasia (overgrowth of abnormal-appearing cells lining breast lobules and ducts)

These categories indicate risk of the abnormality becoming breast cancer (Schnitt 2003; Hartmann 2005; Dupont 1985; Guray 2006):

  • Women with non-proliferative changes generally do not have increased breast cancer risk.
  • Women whose benign breast abnormalities are proliferative without atypia have a 1.3- to 2-fold increased risk of breast cancer compared with women who have non-proliferative benign breast disorders.
  • Women with atypical hyperplasia have a 4- to 13-fold increased risk of breast cancer compared with women who have non-proliferative changes.
    • There are two types of atypical hyperplasia: ductal and lobular.

Table 1: Types of Benign Breast Disease



Breast Cancer Risk


Simple cyst

Generally not associated with breast cancer

Complex cyst

Papillary apocrine changes

Epithelial-related calcifications

Mild hyperplasia of the usual type

Ductal ectasia

Non-sclerosing adenosis

Periductal fibrosis

Proliferative without atypia

Sclerosing adenosis


(1.3- to 2-fold increased risk)

Intraductal papilloma


Ductal hyperplasia of the usual type


Radial scar


Atypical hyperplasia

Ductal atypical hyperplasia


(4- to 13-fold increased risk)

Lobular atypical hyperplasia

(Guray 2006; Visscher 2014; Hartmann 2005; Jones 2011; Alvero 2015)

Other Breast Abnormalities

A variety of other breast abnormalities may cause signs and symptoms similar to those caused by fibrocystic changes.

Table 2: Other Breast Abnormalities that may Resemble Fibrocystic Changes


Associated Breast Cancer Risk




Lipomas may be confused with other causes of fibrocystic changes; may require excisional biopsy to confirm the diagnosis.

Fat Necrosis


Usually a result of trauma



Uncommon and painless



Multiple subtypes with different characteristics



May be confused with inflammatory breast cancer

Apocrine metaplasia


Common finding in women over age 25

Complex fibroadenomas


Refers to the presence of multiple types of abnormalities in addition to fibroadenoma

Phyllodes tumor

Can refer to both benign and malignant growths

Rapid rate of growth

(Guray 2006; Amin 2013; Lanng 2004; Rosa 2010; Parker 2001; Wells 2007)

The Cause of Fibrocystic Changes

The precise cause of fibrocystic changes is not known, but hormonal imbalances are strongly implicated as a contributing factor (Alvero 2015; Jones 2011). A relative deficiency of progesterone or excess of estrogen during the luteal phase of the menstrual cycle may lead to fibrocystic changes (Vorherr 1986; Horner 2000; Carbonaro 2012). The luteal phase occurs after ovulation, when an egg is released by an ovary; this phase lasts until the onset of the menstrual period. The luteal phase usually lasts 14 days (UCSF 2015). During the luteal phase, breast tissue may become tender and lumps may increase in size (Cleveland Clinic 2014).

Fibroadenomas, which are a type of fibrocystic change composed of fibrous and glandular tissue, are particularly sensitive to hormonal changes (Yu 2013; Greenberg 1998). In fact, these breast abnormalities can produce milk during pregnancy and they recede beginning in perimenopause as hormone levels decline. Therefore, women may be more likely to experience symptoms caused by a fibroadenoma during pregnancy and lactation (Yu 2013). Also, women who begin oral contraceptives before age 20 have an increased risk of developing fibroadenomas (Yu 1992; Estevao 2007; Guray 2006).