Mammography is an X-ray examination of the breast. There are 2 types of mammography:
- Screening mammography detects breast disease in a woman who does not have any symptoms.
- Diagnostic mammography is used to help make a diagnosis in a woman who has breast complaints such as a lump or an abnormality that was discovered during a screening mammogram.
Calcification in the breast - what does it mean?
Calcifications are tiny deposits of calcium within the breast that appear as white dots on mammograms (see Figure 1).
While most calcifications are noncancerous, some are associated with breast cancer.
Noncancerous causes of calcifications
There are many noncancerous causes of calcium in the breast including:
- Fibroadenoma - a noncancerous growth that degenerates over time leaving behind large, chunky deposits of calcium that can look like popcorn (see Figure 2).
- Scar tissue in the breast - calcium can be deposited in scar tissue after, for instance, a surgical biopsy (removal of a tiny sample of tissue for examination) or a reduction mammoplasty (breast reduction surgery).
- Fluid-filled lumps - calcium can appear with a cyst - a noncancerous (benign) lump that contains fluid. When a mammogram is taken at a horizontal angle with a patient standing, the calcium may be seen at the bottom of a cyst, causing a slightly curved fine line that can be easily diagnosed (see Figure 3).
Determining whether calcifications are cancerous
A mammogram can often accurately diagnose most calcium deposits as either cancerous or benign. The in-between varieties require additional mammograms, which are sometimes taken at different angles than the standard one, often with magnification.
Sometimes a technique called spot compression is used to squeeze only a part of the breast. Although spot compression is more uncomfortable than the full-breast device used for the routine pictures, the slightly greater discomfort is worth the greater detail that becomes visible on the mammogram.
If there is breast cancer, a calcification may occur along with a lump, or on its own which can be due to noninvasive "in situ" cancer. With this type of cancer, the cancer cells are located inside the milk duct - they have not yet invaded through the wall of the duct.
If the radiologist believes that the calcification is highly likely to be noncancerous, a biopsy (removal of a tiny piece of tissue for examination) is usually not needed. However, follow-up mammograms are often recommended within 6 months to confirm that cancer is not present. If there is even a small chance that a cancer is present, the radiologist will recommend that some of the calcium be removed and checked by a needle biopsy or surgery.