Evaluation of palpable breast masses.

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.