How are the types and causes of breast lumps diagnosed?
A manual examination of the breast is an important screening method for detecting cancer, and it is the first step in the evaluation of a breast lump. Unfortunately, the manual examination of the breast is not precise. However, if a mass can be felt manually, it is important to estimate the location of the mass so that the mammogram and/or other diagnostic examinations can focus on that particular area. A doctor also inspects any suspicious skin changes that may be a sign of breast cancer. Since the manual examination can miss breast cancer, mammography is also an important screening tool.
Women with a breast lump need to have a mammogram of both breasts. A mammogram is estimated to be able to detect about 90% of breast cancers. This means that about 10% of breast cancers are missed by mammography. Therefore, if a woman or her physician feels a lump and the mammogram is normal, further studies or biopsies are carried out to rule out cancer. Sometimes, a certain pattern of calcium deposits appears on the mammogram that makes the doctor suspicious of cancer. In these cases, it is often recommended that a biopsy be taken that is guided by mammogram images to be sure the correct area is sampled.
Ultrasound is useful in the evaluation of breast lumps. It can distinguish between a cyst, which is filled with fluid and a solid lump (which may or may not be cancerous). The first step in the evaluation of a breast lump is to determine whether it is a cyst or solid mass. This is best accomplished by performing an ultrasound examination. In a young woman, where a benign cyst is anticipated and, the ultrasound is confirmatory, she may not require any procedures or biopsies. If it is unclear on the ultrasound whether the lump is entirely cystic in nature, a further evaluation is usually recommended.
Magnetic resonance imaging (MRI) is becoming more widely used in the evaluation of breast lumps because it is particularly sensitive to small abnormalities in breast tissue. MRI is a special radiology technique designed to image internal structures of the body using magnetism, radio waves, and a computer to produce the images of body structures. Cancers generally have a greater blood supply than non-cancerous growths. The images obtained from an MRI may help determine whether a particular area is cancerous as the MRI exhibits greater contrast in those areas with an increased blood supply. In most cases, MRI is performed if results of mammography and ultrasound evaluations are not conclusive.
MRI also has limitations. For example, MRI cannot detect the presence of calcium deposits, which can be identified by mammography and may be a sign of cancer.