e6-14: Mastalgia

Breast pain, also known as mastalgia, is a common condition and affects up to 70% of women during their lifetime. Mastalgia is classified as cyclical, noncyclical, or extramammary. Cyclical mastalgia is the most common type of breast pain and is characterized by discomfort that is most prominent during the luteal phase of ovulation, improving with menses. Noncyclical mastalgia has no relationship to the menstrual cycle and is more common among women in their fourth or fifth decades of life. Causes of noncyclical mastalgia include duct ectasia, mastitis, large breast size (with stretching of Cooper ligaments), medications, pregnancy, thoracic vein thrombophlebitis, trauma, or prior breast surgery. Although uncommon, advanced breast cancer, invasive lobular carcinoma, and anaplastic carcinoma of the breast may also present with mastalgia. Extramammary mastalgia is caused by pain that is referred from other anatomic locations, including the chest wall, heart, gallbladder, or spine.

A. Symptoms and Signs

Cyclical mastalgia is typically diffuse, bilateral, and associated with either the menstrual cycle or cyclically administered hormonal therapies such as contraceptives or menopausal hormone therapy. Conversely, noncyclical mastalgia, which may be constant or intermittent, is variable in location and can involve one or both breasts. Chest wall pain, a frequent cause of extramammary mastalgia, typically causes unilateral, burning pain that may be either localized or diffuse.

A careful physical examination is essential in all women who report breast pain. Extramammary causes of mastalgia, such as inflammation of the pectoralis major muscle or costochondral junction, can usually be diagnosed through careful palpation. Mondor disease, which is caused by superficial thrombophlebitis of the lateral thoracic vein, is associated with a red, tender, palpable cord.

B. Imaging

An ultrasound, mammogram, or both should be obtained in women who have a palpable breast mass or in whom Mondor disease is suspected since this diagnosis may be associated with breast cancer.

Additionally, imaging should be considered for women who experience noncyclical, unilateral, or localized mastalgia that is not clearly associated with a specific diagnosis, particularly when pain is progressive. According to the American College of Radiology Appropriateness Criteria, ultrasound is the preferred imaging modality for women under the age of 30 years because it is more accurate than mammography in this age group. Mammography and ultrasonography should be performed in women over the age of 40 years, and use of both imaging modalities should also be considered in selected patients aged 30–39 years.

Women who are up to date on routine screening mammography, who present with cyclical or nonfocal bilateral breast pain, and who have normal physical examination findings do not require additional breast imaging.

Malignancy must be ruled out in all patients with mastalgia, though it is uncommon for breast pain to be the sole presenting symptom of underlying malignancy in the absence of other examination findings. A careful history and physical examination help distinguish patients with clinical abnormalities, such as skin changes or a palpable breast mass, who will benefit from diagnostic imaging (beyond routine, age-appropriate screening), tissue biopsy, or referral to a breast specialist. Extramammary causes of breast pain include chest wall pain, spinal or gallbladder disease, and myocardial ischemia. Cyclical and noncyclical mastalgia are easily differentiated by assessing the temporal relationship between the patient's pain and menstrual cycle or cyclical hormonal treatment. While cyclical pain is often related to hormonal fluctuations, noncyclic pain has a broader differential diagnosis, including trauma, inadequate breast support, mastitis, ductal ectasia, and medications.

Women with cyclical mastalgia who have a normal physical examination and are up to date on routine mammographic screening should be reassured about the benign nature of their symptoms and monitored closely. Many patients do not require additional treatment after reassurance.

Cyclical and noncyclical mastalgia often improve with use of a supportive bra that fits properly. Topical NSAIDs, such as diclofenac gel, improve localized breast pain for both types of mastalgia and carry minimal risk of harm. Studies do not support the use of evening primrose oil, vitamins, or gamma-linoleic acid for management of mastalgia. Mastalgia associated with hormonal therapies may require treatment modifications, such as skipping the placebo week with combined hormonal contraceptives or discontinuing menopausal hormone therapy.

Pharmacologic therapies include danazol, tamoxifen, and bromocriptine; however, these medications should be reserved for patients with severe pain that has not responded to conservative management. Danazol is the only FDA-approved treatment and is associated with a significant reduction in pain when compared to placebo. However, this medication is associated with adverse effects (menstrual irregularities, weight gain) and is contraindicated in women who are attempting to become pregnant. Bromocriptine, which acts by inhibiting the release of prolactin, has been shown to reduce pain although less effectively than danazol in clinical trials. Benefits have also been seen for treatment with selective estrogen receptor modulators; tamoxifen can reduce discomfort in 75–90% of women who are treated for 3 months. Symptoms may recur upon cessation, but longer durations of treatment are not recommended due to the risks of endometrial proliferation and venous thromboembolism.

Symptoms of cyclical and noncyclical mastalgia improve without pharmacologic treatment in most women.

Patients with mastalgia and a palpable breast mass should be referred to a breast specialist.