Screening tests that you may be given to determine if you have breast cancer may include one or more of the following:

• Mammography -A mammogram is an x-ray of your breast used to diagnose unusual changes, such as a lump, pain, nipple thickening or discharge, or a change in breast size or shape. A diagnostic mammogram is also used to check abnormalities detected on a screening mammogram and generally involves additional views of the breast that aren't done with a screening mammogram. It is a basic medical tool and is appropriate in checking out breast changes, regardless of your age.
  
• Ultrasonography - This test uses high-frequency sound waves, not heard by humans. The sound waves enter your breast and bounce back. The pattern of their echoes produces a picture called a sonogram, which is displayed on a screen. This exam is often used along with, but not instead of, mammography.
  
• MRI (magnetic resonance imaging) - This form of screening uses magnets to provide a three-dimensional view of your breast. Studies find it is better at detecting breast cancer than mammography, particularly in younger (premenopausal) women with dense breasts. However, there are concerns that MRI can be too sensitive, detecting findings that do not turn out to be cancerous (false positives). Women at high risk of developing breast cancer should have an MRI every year along with a screening mammogram beginning at age 30. Women at high risk are those who have tested positive for the BRCA1 or BRCA2 gene mutation, or who have a mother, sister, or daughter who tested positive. Women are also considered high risk if they have had at least two close relatives with breast cancer or if they had chest radiation for Hodgkin's disease. MRI is not considered a screening test for the average woman at risk of developing breast cancer, and it should only be done in carefully selected women. 

  If the screening tests show possible areas of concern, a tissue sample (biopsy) will be taken.

  Types of breast biopsy procedures include, but are not limited to, the following:
• Fine needle aspiration biopsy -A very thin needle is placed into the lump or suspicious area to remove a small sample of fluid and/or tissue. No incision is necessary. A fine needle aspiration biopsy may be performed to help tell a cyst from a solid lump.
  
• Core needle biopsy - A large needle is guided into a lump or suspicious area to remove a small cylinder of tissue (also called a core). No incision is necessary.
  
• Surgical biopsy (also called an open biopsy) - Your surgeon removes part or all of a lump or suspicious area through an incision into your breast. There are two types of surgical biopsies. During an incisional biopsy, a small part of the lump is removed. During an excisional biopsy, the entire lump is removed.
  
  In some cases, if your breast lump is very small and deep and hard to locate, the wire localization technique may be used during surgery. With this technique, a special wire is placed into the lump using x-rays for guidance. Your surgeon follows this wire to help locate the lump.
  
  Special instruments and techniques may be used to guide the needles and to assist with biopsy procedures. These include, but are not limited to, the following:
  
• Stereotactic biopsy - Stereotactic biopsy finds the exact location of a breast lump or suspicious area. It does this by using a computer and mammogram results to create a three-dimensional (3-D) picture of your breast. A sample of tissue is removed with a needle.
  
• Mammotome breast biopsy system (also called vacuum-assisted biopsy) - A type of tube is inserted into your breast lump or mass. The breast tissue is gently suctioned into the tube. A rotating knife removes the tissue.
  
• Ultrasound-guided biopsy - This technique uses a computer and a transducer that sends out ultrasonic sound waves to create images of your breast lump or mass. This technique helps to guide the needle biopsy.