Benign Disease of the Breast
The breast consists of two types of tissues: glandular and
stromal (supportive) tissues. Lobules and ducts make up the glandular
portion of the breast, while fatty and fibrous connective tissue make up the
stroma. Any of these tissues of the breast can undergo changes which can
cause a patient to have symptoms. Cysts, fibroadenomas, fibrocystic
change, infection, and inflammation are all examples of processes which can
manifest in the breast, but are considered benign.
Women can experience various kinds of breast lumps and changes,
particularly during their menstrual cycle, pregnancy, or with aging that can
mimic breast cancer, even when they are not. Since most breast lumps and
changes are in fact benign, it is important to distinguish these lesions
from their malignant counterparts, in order to alleviate undue anxiety.
The most common benign diseases of the breast are presented
below. These encompass the majority of presenting breast complaints in the
ambulatory surgery setting.
Nipple discharge is a symptomatic problem which causes patients
both anxiety and discomfort. It can occur in either sex, but predominantly
occurs in females. It is most often due to a benign process, and can occur
at any age, from infancy to adulthood. When evaluating nipple discharge,
the first step is to determine whether it is a result of a physiologic or
pathologic process. For example, women using contraceptives or hormone
replacement therapy can have non-clinically significant nipple discharge,
secondary to the effects of the medications on the breast epithelium.
Physiologic discharges tend to occur only with compression of
the nipple or breast and are characterized by multiple duct involvement. These
discharges are most often bilateral, and their source is often revealed by a
careful history. After exclusion of malignancy by mammography, reassurance
is often the only therapy necessary.
Nipple discharges are classified as pathologic if they are
spontaneous, bloody, or associated with a mass. They tend to be unilateral
and confined to one duct, and their risk for malignancy increases in patients
over 50 or when associated with positive mammographic or galactographic
findings. The most common cause for pathologic nipple discharge is an
intraductal papilloma, a benign local proliferation of ductal epithelial cells.
Other causes include duct ectasia (second most common cause), cysts, and
In either case, the work-up should include localization of the
affected duct (or ducts), and examination for occult blood. A diagnostic
mammogram is useful for identifying non-palpable masses and calcifications.
All patients with a spontaneous, unilateral, or bloody discharge should be
referred for surgical evaluation. A terminal duct excision is both
diagnostic and, for discharges that turn out to have a benign cause,
Fibroadenomas are among the most common benign tumors and are
typically not considered to have malignant potential. They are composed of
stromal and epithelial elements and represent a hyperplastic process in a
single, terminal ductal unit. Within the breast, two
kinds of breast stroma exist: intralobular and interlobular. Intralobular stroma
contains lobules composed of 6-10 major ductal systems surrounded by a
myxomatous stroma, and it is from this stroma that fibroadenomas arise.
They typically occur in younger women (teens to 30's), and
present as palpable or non-palpable, oval, freely mobile, rubbery masses.
Usually a solitary lesion, they present in a range of sizes, from very small (<1
cm) to extremely large (up to 15 cm). Although usually only a single lump
presents itself, about 10-15% of women may have multiple masses, affecting both
Fibroadenomas are most often painless and appear to respond to
hormonal changes. During the reproductive years, and during pregnancy in
particular, they may increase in size. After menopause, they tend to
regress in size.
Evaluation is usually made by ultrasound (for women under 30) or
ultrasound/mammogram for women over 30. On ultrasound, fibroadenomas are
circumscribed, homogeneous, oval, hypoechoic masses, often with gentle
lobulations and a smooth, thin, echogenic capsule. On mammogram, they
appear as circumscribed oval or round masses, which occasionally have coarse
Definitive diagnosis, however, is made by
fine needle aspiration or open biopsy, with FNA the preferred evaluation. If a biopsy
indicates that the lump is a fibroadenoma, the lump may be left in place or
removed, depending on the patient and the lump. If left in place, it may be
watched over time with physical examinations, mammograms, and ultrasounds.
Alternatively, the lump may be surgically removed, depending on the features of
the lump and the patient's preferences. Typically, however, approximately 50% of
fibroadenomas will resolve on their own within 5 years, so conservative "watch
and wait" treatment is plausible.
Fibrocystic breast disease (FBD) is the most common cause of breast
lumps in women of childbearing age. Although not generally considered a
"disease" per say, fibrocystic change is a manifestation of normal physiologic
changes, which occur in response to menstrual hormonal changes. It is
encountered so often, that some doctors consider it a normal variant. The
condition is characterized by freely mobile masses (typically multiple) in
the breast tissue, that are tender to palpation. Breast tissue is often
described as "lumpy and bumpy".
Although the exact cause of fibrocystic change is unknown, it is
thought to be a result of the way breast tissue responds to monthly hormonal
changes (estrogen, progesterone, and even prolactin) in premenopausal women.
This comes from the observation that symptoms are generally worse before the
onset of menses and improve afterwards. In addition, fibrocystic change is
rare in postmenopausal women, unless receiving hormone replacement therapy (HRT).
The symptoms of fibrocystic breast disease can range from mild
to severe. Patients may report feeling lumps enlarging or regressing,
breast tenderness (particularly to touch), nipple discharge (prolactin
stimulated from lump pressing against a milk gland) and changes in nipple
sensation, such as itching.
Diagnosis is made with a detailed medical history and physical
exam, with emphasis on changes in symptomology with time (before, during , and
after a menstrual cycle). Mammography and ultrasound may be helpful,
except in younger women with denser breasts. Definitive diagnosis can be
made with FNA or excisional biopsy, although a good clinical exam is often all
that is necessary. Treatment is mainly reassurance and pain relievers
Breast cysts are very similar in nature to fibrocystic breast
change, however, unlike the latter, they exist as true "cysts". Like FBD,
they tend to occur in response to hormonal changes; typically when the breast is
stimulated by an excess of estrogen. As such, they are the most common
cause of a breast mass in women in their 40's and 50's, or postmenopausal women
taking HRT. They are less prevalent in premenopausal women under 40.
Breast cysts are classified according to how they appear on
ultrasound. Simple cysts are well-defined, round or oblong masses which
the ultrasound signal passes readily through. They look very dark on
ultrasound and have a thin, distinct, border. Complex cysts, on the other
hand, may be less well-defined. The ultrasound image is usually
grayish-black, with fuzzy edges, as the signal does not pass easily through
On physical exam, it is often difficult to distinguish a cyst
from a solid mass. Ultrasound or FNA must be employed to establish a
definitive diagnosis. Most aspirated cysts yield straw-colored or
green-tinged fluid and the cyst resolved following aspiration (the capsule
involutes) . Unless bloody fluid or a residual mass remains following
aspiration, routine cytologic examination of cyst fluid is not indicated, as
there is a low likelihood of cancer. Bloody fluid or a residual mass does,
however, warrant further evaluation with diagnostic mammography and biopsy, in
addition to cytologic analysis of aspirated fluid
Patients with a solitary breast cyst should be reexamined four
to six weeks after cyst aspiration to determine if the cyst has recurred.
Aspiration is still an appropriate first step in the management of a breast
cyst, but clinical follow-up after aspiration is essential.