Evaluation of palpable breast masses

American Family Physician,  May 1, 2005  by Susan Klein

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Palpable breast masses are common and usually benign, but efficient evaluation and prompt diagnosis are necessary to rule out malignancy. A thorough clinical breast examination, imaging, and tissue sampling are needed for a definitive diagnosis. Fine-needle aspiration is fast, inexpensive, and accurate, and it can differentiate solid and cystic masses. However, physicians must have adequate training to perform this procedure. Mammography screens for occult malignancy in the same and contralateral breast and can detect malignant lesions in older women; it is less sensitive in women younger than 40 years. Ultrasonography can detect cystic masses, which are common, and may be used to guide biopsy techniques. Tissue specimens obtained with core-needle biopsy allow histologic diagnosis, hormone-receptor testing, and differentiation between in situ and invasive disease. Core-needle biopsy is more invasive than fine-needle aspiration, requires more training and experience, and frequently requires imaging guidance. After the clinical breast examination is performed, the evaluation depends largely on the patient's age and examination characteristics, and the physician's experience in performing fine-needle aspiration.

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Breast carcinoma masses have a variety of etiologies, benign and malignant. Fibroadenoma is the most common benign breast mass; invasive ductal is the most common malignancy. (1) Most masses are benign, but breast cancer is the most common cancer and the second leading cause of cancer deaths in women. (2) Although most breast cancers occur in women older than 50 years, 31 percent of women diagnosed with breast cancer between 1996 and 2000 were younger than 50 years. (3) An efficient and accurate evaluation can maximize cancer detection and minimize unnecessary testing and procedures.

Initial Evaluation

HISTORY

A thorough patient history is necessary for the physician to identify risk factors for breast cancer. Some risk factors are well established, and others indicate probable or possible increased risk (Tables 1 and 2). (4-14)

PHYSICAL EXAMINATION

A complete clinical breast examination (CBE) includes an assessment of both breasts and the chest, axillae, and regional lymphatics. In pre-menopausal women, the CBE is best done the week following menses, when breast tissue is least engorged. With the patient in an upright position, the physician visually inspects the breasts, noting asymmetry, nipple discharge, obvious masses, and skin changes, such as dimpling, inflammation, rashes, and unilateral nipple retraction or inversion. (15)

With the patient supine and one arm raised, the physician thoroughly palpates breast tissue on the raised-arm side in the superficial, intermediate, and deep tissue planes (i.e., the "triple touch" technique); axilla; supraclavicular area; neck; and chest wall, assessing the size, texture, and location of any masses (Figure 1). (15) The physician should note the size of the masses to document changes over time. Next, the physician should inspect the areola-nipple complex for any discharge. CBE sensitivity can be improved by longer duration (i.e., five to 10 minutes) and increased precision (i.e., using a systematic pattern, varying palpation pressure, and using three finger pads and circular motions). (15,16)

Benign masses generally cause no skin change and are smooth, soft to firm, and mobile, with well-defined margins. Diffuse, symmetric thickening, which is common in the upper outer quadrants, may indicate fibro-cystic changes. Malignant masses generally are hard, immobile, and fixed to surrounding skin and soft tissue, with poorly defined or irregular margins. (15) However, mobile or nonfixed masses can be cancerous. Infections such as mastitis and cellulitis tend to be erythematous, tender, and warm to the touch; they may be more circumscribed if an abscess has formed. Similar symptoms may occur in patients with inflammatory breast cancer. Therefore, caution should be used in assessing patients with suspected breast infections.

Digital palpation of the breast is effective in detecting masses and can help determine whether a mass is benign or malignant. (15,17) CBE can detect up to 44 percent of cancers, up to 29 percent of which would not have been detected by mammography. (15,17) Despite its accuracy, CBE alone is not adequate for definitive diagnosis of breast cancer. Further evaluation, including follow-up examinations, imaging, and tissue sampling, is required in all patients with breast masses.

Imaging

ULTRASONOGRAPHY

Ultrasonography can effectively distinguish solid masses from cysts, which account for approximately 25 percent of breast lesions. (18,19) When strict criteria for cyst diagnosis are met, ultrasonography has a sensitivity of 89 percent and a specificity of 78 percent in detecting abnormalities in symptomatic women. (18) Recurrent or complex cysts may signal malignancy; therefore, further evaluation of these lesions is required. (19)