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Fibrocystic Breast Disease
Breast nodules are a frequently presented gynecologic complaint. These nodules have two chief causes: benign breast disease and cancer. However, benign breast disease is the most common cause of nodules and can stem from cyst formation, obstructed ducts, inflammation, or infection. Although benign breast nodules have several causes and manifest themselves differently, for purposes of this discussion, all fibrous nodules or lumps will be referred to as fibrocystic breast disease (FBD).
According to the National Cancer Institute/National Institutes of Health (2001a,b), fibrocystic breast disease (FBD) is a common condition that affects many women at some time in their lives. FBD is most common between the ages of 30 and 50 (AMA 1989), but younger women as well as menopausal women taking hormone replacement therapy (HRT) may also experience FBD (Imaginis 2000). More recently, some physicians have preferred to call FBD, fibrocystic breast "condition" or "change" (FBC).
The symptoms of FBD can vary significantly. Some women experience severe breast tenderness and pain with multiple lumps in both breasts. Other women have only mild tenderness with no detectable lumps. In some women the symptoms are relatively constant, while in others the symptoms come and go either monthly or over several months. According to the National Cancer Institute (2001a), the chances of developing FBD are greater in women who have never had children, women who have irregular menstrual cycles, or women who have a family history of FBD or breast cancer.
FBD is a condition generally characterized by lumps that move freely in the breast tissue and vary in texture and size (Lark 1996). However, because the clinical signs of breast cancer are not easily distinguished from benign breast conditions, all breast lumps should be examined by a physician and not be assumed to be benign. Only a physician can determine the nature of breast lumps or changes (National Cancer Institute 2001a).
Because FBD is a benign condition, it usually does not lead to breast cancer (American Cancer Society 1991, 1997; National Cancer Institute 2001b). Fortunately, only about 5% of FBD cases involve the type of changes that would be considered a risk factor for developing breast cancer. However, benign conditions may eventually result in calcifications (Anon. 1998). Calcifications are quite small--sometimes as small as a grain of salt--and cannot be detected during a routine exam; however, calcifications may be detected by routine mammography. Since calcifications may be associated with some types of pre-malignant lesions, it is important to follow your physician's recommendations concerning the frequency of mammography (AMA 1989).
NORMAL BREAST TISSUE
The breast is composed of 15-20 lobes of milk-secreting glands that are embedded in fatty tissue. Ducts link the lobes of these glands and have an outlet through the nipple. The area between the lobules and ducts is filled with fatty tissue. Breast tissue itself contains no muscles; however, there are small, very fine ligaments throughout the breast that attach to the skin and determine the shape of the breast. There are no muscles in the breast itself, although pectoral muscles lie just under each breast and over the ribs (AMA 1989).
The breasts undergo changes each month when a female begins to have menstrual periods. Hormones that are implicated in development of breast mammary glands and worsening premenstrual breast symptoms are estrogen and progesterone, the main female hormones, and prolactin, the milk release hormone secreted by the pituitary gland (Lark 1996). An increase in prolactin may also be responsible for some FBC changes because higher levels of p rolactin seem to be connected with a higher occurrence of FBC. (Prolactin levels of over 100 ng/mL may be a causative factor). Often the painful symptoms of FBD will decrease once menstruation begins. In some women, however, the repeated cycles of hormonal stimulation result in chronic inflammation and development of fibrous tissue. When fibrous tissue makes it more difficult for the fluid in breast cysts to escape and be normally absorbed by a woman's body, the cysts become denser, which can cause pain and pressure on surrounding tissues (Lark 1996). This fibrous tissue is similar to the type of tissue in ligaments and scars and feels firm, thick, rubbery, and ridge-like. It may also feel like small or large beads scattered throughout the breast.
In addition to estrogen, progesterone, and prolactin, all naturally occurring female hormones, many other natural hormones (hypothalamic, other pituitary hormones, thyroid, parathyroid, adrenal, pineal, pancreas, ovarian, and duodenal hormones) can also contribute to FBD (Ayers 1983; AMA 1989). Environmental estrogens, called xenoestrogens, may also contribute to human hormone levels. Xenoestrogens come from phytoestrogens (produced by plants), dietary estrogens from meat and dairy products, and many other chemicals such as pesticides, fertilizers, alklyphenols (used in detergents), and plastics (food packaging) (Nimrod et al. 1996). Additionally, as women approach menopause, they have an additional, complicated decision to make concerning the use of synthetic hormone replacement therapy (HRT) (Lundstrom et al. 2001; Mayo Clinic 2001; Women's Health Initiative Investigators 2002).
Breast Nodules
As stated earlier, because breast tissue is naturally a glandular type of tissue, almost all women develop nodules or lumps in their breasts at some time or another. Lumps, also called "dominant lumps," feel different from surrounding tissue (AMA 1989). Some may be quite large, while others are small and even diffuse over time (Lark 1996). Fibrous tissue in the breast may even be mistaken for a lump. Breast nodules or lumps are the result of several medical causes, including cysts, fibroadenomas, areolar gland abscesses, breast abscesses, intraductal papillomas, mammary duct ectasia, mastitis, Paget's disease, and cancer (Anon. 2000).
Benign Nodules
Cysts
Cysts are the most common cause of nodules or breast lumps. Cysts are usually smooth, round, fluid-filled, and slightly elastic. Although the fluid that comes from a cyst is often discolored, the color of the fluid is of little cause for concern unless it is bloody. Cysts occur as an isolated lump, in clusters, or widespread with well-defined lumps of various sizes. Cystic lumps are mobile and do not attach themselves to underlying breast tissue; therefore, cysts do not produce tissue deviation or dimpling. Mobility is one major characteristic that differentiates cysts from malignant nodules. However, cysts are sometimes accompanied by thickened adjacent tissue that is palpable and not so mobile. Breast cysts may also produce a discharge from the nipple that varies from clear and watery to sticky (AMA 1989).
Cysts frequently occur in the upper outer quadrant and the underside of the breast. Symptoms range from a feeling of fullness or heaviness to a dull ache, extreme sensitivity, or a burning sensation. For some women, these symptoms may be severe, making exercising or sleeping on their stomachs painful.
Cysts also often increase in size and tenderness in response to the monthly menstrual cycle because breast tissue undergoes changes related to the normal rise and fall of hormone levels (Lark 1996). After menstruation, the changes and symptoms sometimes abate. Physicians recommend that the best time for breast examination is about 7-10 days after the start of menstruation when breast tissue is more likely to be at its most normal state. Sometimes, after menopause, FBD symptoms completely disappear or become less noticeable (without HRT) (Imaginis 2000).
The occurrence of multiple cysts in one or both breasts is also common in FBD (also called fibroadenosis or chronic cystic mastitis) (Anon. 2000). If a mass is determined to be a cyst, the next step is to determine if it is a simple cyst (one compartment) or a complex cyst (more than one compartment within the cyst). Simple cysts are very unlikely to be malignant.
Sclerosing Adenosis
A benign condition with excessive tissue growth in the lobules of the breast is sclerosing adenosis (National Cancer Institute 2001b). The condition frequently causes breast pain. Sclerosing adenosis may produce lumps and appears on a mammogram as a calcification (a small deposit of calcium) in breast tissue.
Intraductal Papillomas
Small, wart-like, benign growths that project into the breast ducts near the nipple are intraductal papillomas (National Cancer Institute 2001b). They usually occur singly, but can also appear as multiple lesions. The smaller nodules are difficult to palpate. The primary sign of intraductal papilloma is nipple discharge, either clear or bloody. Breast pain and tenderness may occur.
NODULES WITH POTENTIAL FOR CANCER
Complex Cysts
Complex cysts have more than one compartment within the cyst. Ultrasonography is valuable in differentiating simple cysts from complex cysts or solid masses (Bassett et al. 1991). Complex cysts are somewhat more likely to be cancerous, so doctors will often order further tests, beginning with fine needle aspiration and perhaps a biopsy, to be certain the cyst is not cancerous or pre-cancerous.
Fibroadenomas
Fibroadenomas (sometimes called adenofibromas) are smooth, firm, benign tumors that are extremely mobile, feel slippery, and move around easily in the breast. They consist of structural (fibro) and glandular (adenoma) tissue (Anon. 2000, National Cancer Institute 2001b). Fibroadenomas feel round with well-defined margins and vary from pinhead in size to very large. They grow rapidly and usually occur near the nipple or on the outside of the upper quadrant. Fibroadenomas occur most often in women in their 20s and 30s and occur twice as often in African-American women as in other American women (National Cancer Institute 2001b). When aspirated, if there is no fluid in the lump, it is most likely a fibroadenoma. Fibroadenomas do not cause pain or tenderness. A "complex" fibroadenoma contains abnormal growths or exhibits abnormal cell changes. Although fibroadenomas themselves do not become cancerous (National Cancer Institute 2001b), they can act as markers for the disease. Women with a family history of breast cancer who also develop complex fibroadenomas might be at a higher risk for developing cancer than other women. Fibroadenomas are not difficult to remove and rarely recur.
Paget's Disease
A slow-growing intraductal carcinoma that begins as a scaling, eczema-like lesion on the nipple is called Paget's disease (Anon. 2000). The nipple becomes red and irritated and the lesion extends along the skin and into the ducts. The lesion can progress to a mass located deep in the breast.
Phyllodes Tumor
Phyllodes tumor is a breast tumor that might be malignant (Mazy et al. 1999). Phyllodes tumor is a rare type of breast tumor, similar to a fibroadenoma, but it is composed of an overgrowth of fibrous connective breast tissue that can become quite large. If malignancy is discovered (rare) through biopsy, the tumor and a margin of normal breast tissue are removed surgically.
FACTORS AFFECTING INCREASED RISK OF BREAST CANCER
When a woman finds a breast nodule, the first concern is that it might be cancerous. Most of the time, breast nodules are not cancerous (benign). According to Hurley et al. (1997), there are three basic, agreed-upon classifications of benign breast disease: nonproliferative, proliferative without atypia, and atypical hyperplasia. However, there can be an association with benign changes in the breast in young women and an increased risk of breast cancer with age, particularly later in life. Therefore, pathologists sometimes add comments to the pathology report indicating whether or not benign changes are relevant to an increased risk of cancer. One study followed 644 women with breast nodules between 1976 and 1982. The researchers found a relationship between subsequent cancer in women with multiple cysts and in 15 of the women whose cysts had been aspirated. The authors concluded that women with multiple breast cysts that have been aspirated have an increased risk of breast cancer. These women should perform more breast self-examinations and have follow-ups accordingly (Bundred et al. 1991).
Benign breast conditions are more often found in premenopausal women (Ernster 1981; Bodian 1993a). Breast cancer occurs more often in postmenopausal women (75% of cases) (NBCC 1999). Estimating the risk for future breast cancer from a benign condition is difficult: the extent of mammography screening differs in the population and often, significant time passes between diagnosis of benign disease in a younger woman and the increased risk for breast cancer development in older women. Because benign breast disease is difficult to distinguish from malignant disease, diagnostic biopsy is required for a definitive diagnosis (NBCC 1999).
Women with biopsy-confirmed benign disease do appear to have an overall modest increase in risk for subsequent development of breast cancer, particularly for more hyperplastic or epithelial (the covering or lining) proliferative forms. However, the evidence regarding the risk of breast cancer for nonproliferative conditions is conflicting. Some research found that the risk of breast cancer for women with nonproliferative disease is about double that of women without benign disease (Bodian et al. 1993b), while others find that lesions with no proliferative changes were not associated with an increased risk (Oza et al. 1993; Henderson et al. 1996; NBCC 1999). According to Hurley et al. (1997) atypical hyperplasia is a risk factor, but it is not with certainty followed by breast cancer; risk applies to both breasts, with greater risk on the affected side. There is no means to predict which women will go on to develop breast cancer and the effectiveness of current screening and management methods is unknown. Further complicating a physician's ability to predict a woman's risk for breast cancer is that most women do not have a history of biopsy for a benign lesion. Additionally, at the time of this writing there is no generally agreed upon classification of mammography patterns of breast tissue that is a predictive measure of which conditions are indicative of increased risk (Bodian et al. 1993c; NBCC 1999). |