History and physical examination A careful history in women with a breast lump includes: The precise location of the lump How it was first noted (accidentally, by breast self-examination, or during a screening clinical breast examination or mammogram) If and how long the patient has noted its presence Whether there is any accompanying nipple discharge Whether the lump has changed in size Whether the lump waxes and wanes in size at particular times in the menstrual cycle. Benign cysts may be more prominent premenstrually and regress in size during the follicular phase. Eliciting a past history of breast cancer or breast biopsy (especially one showing atypical hyperplasia), and a history of risk factors for breast cancer (table 1) is important. Breast tissue in normal women is often lumpy. Thus, the physical examination should concentrate upon those factors which may help to differentiate palpable lumps that are breast cancer from benign lesions. A number of "classic" characteristics of cancerous lesions have been described: Single lesion Hard Immovable Irregular borders Size > or =2 cm However, these features individually do not distinguish well between cancers and benign lesions. Caveats to be considered when evaluating breast lumps include: Smooth, well-demarcated lumps are usually benign, according to experts (actual evidence is not available). Although usually painless, breast cancer can be accompanied by pain. In one study, almost 15 percent of cancers were associated with discomfort Nipple discharge is uncommon in cancer and, if present, is unilateral. In one study, 3 percent of cases of unilateral nipple discharge was due to breast cancer; a mass was usually also present Careful examination of the axillae and supraclavicular area for nodal involvement is necessary. While the physical examination may distinguish benign versus malignant breast lumps reasonably, this is not to a degree that is sufficiently reassuring to the physician or patient. Thus, while the history and physical examination are important first steps in the assessment of breast lumps, the evaluation does not stop there.