Most breast lumps are benign, but it is important to have any breast lump assessed by your doctor. Some breast lumps are quite distinct and feel like a firm round ball. Sometimes there merely is a thickening of the tissue which feels different from the mirror- image area of the opposite breast. Breast tissue is often lumpy which can make it difficult to distinguish a discrete lump from the background texture. Feeling the mirror-image area in the opposite breast can be helpful in trying to make this distinction. Hormonal changes can affect the texture of the breast tissue, and it is most helpful to do a breast exam when these changes are at a minimum, 5-7 days after the start of ones menstrual period. There is a great deal of overlap in the appearance of cancerous and benign breast lumps. Although benign lumps tend to be painful, smooth, firm or mobile while breast cancers tend to be painless, hard, irregular or immobile, these characteristics are not reliable for distinguishing benign from malignant (cancerous) lumps.
Any new or changed breast lump should be evaluated by a physician or experienced nurse practitioner. You may be referred to a breast surgeon for an evaluation. This will include a medical history of the characteristics of the breast lump and associated breast symptoms, breast cancer risk factors and your general medical history. A clinical breast examination will be performed. For a woman with a breast lump who is thirty or older, a mammogram will usually be performed if one hasnt be done recently, not only to get more information about the lump, but also to be see if any other findings have developed elsewhere in either breast. An ultrasound can be helpful for any woman with a breast lump to determine if the lump is solid or if it is a fluid-filled cyst. Sometimes an ultrasound will show that a lump is a normal structure, such as a fatty lobule.
Although mammograms and ultrasounds can be very helpful in evaluating women with breast lumps, it is critical to know that a normal mammogram or ultrasound does not rule out the possibility that a breast lump is breast cancer. This is because not all breast
cancers are visible on mammograms and breast ultrasounds. 10-15% of breast cancers cannot be seen on mammograms and this rises to 25% in women under 50. The most common reason for a delay in the diagnosis of a breast cancer is because a woman with a breast lump is told her mammogram is normal and no further evaluation is done. This is particularly true for younger premenopausal women whose mammograms are more difficult to read because of dense breast tissue and for whom the degree of suspicion for breast cancer may be lower since it is often thought of as a disease of older women.
If a breast lump is a cyst, it may not need any intervention, or a fine needle aspiration could be considered. If a lump appears to be related to underlying fibrocystic tissue in a premenopausal woman, the breast examination may be repeated after one or two menstrual cycles to see if it resolves. For the majority of solid breast masses, including ones that show up distinctly on mammogram and/or ultrasound, as well as lumps associated with a negative mammogram and/or ultrasound, a biopsy will be necessary to make a diagnosis. The biopsy may show one of a variety of benign breast findings, such as a fibroadenoma or fibrosytic change, or a benign finding associated with an increased risk for breast cancer, such as atypical ductal or lobular hyperplasia or LCIS. It may reveal breast cancer or a rare breast tumor, such as a phyllodes tumor. Some findings on needle breast biopsies are considered inconclusive, such as papillary or atypical tissue, LCIS or radial scar; these require further evaluation with a surgical biopsy to be sure there is no associated breast cancer.