Sometimes on a mammogram tiny white grains of calcium or microcalcifications are seen. No one knows exactly why, in certain circumstances, the breast lays down calcium. Fortunately the majority of microcalcifications seen on mammogram are due to benign changes and often represents an aging process. There are 4 main classifications of microcalcifications |
1. Malignant Calcifications
These calcifications are very characteristic and are associated with invasive cancer. No one is sure, why the breast lays down microcalcifications in this situation. One theory is that with malignant/premalignant conditions, there is an abnormal production and turn over or death of cells. With cell death, calcium is a by-product.
These calcifications are associated with pre-cancer or ductal carcinoma in situ (DCIS). Sometimes it is easy to distinguish the premalignant calcifications that are associated with DCIS but this is not always the case.
The breast is made up of fat, fibrous tissue and glandular tissue. The glandular tissue comprises ducts and lobules/ milk glands. The ducts are the hollow tubes by which the milk produced in the lobules / milk glands is carried to the nipple. The ducts and lobules/milk glands are lined with cells. It is these cells which can become pre-cancerous and then have the ability to become cancerous.
The actual term ductal carcinoma in situ is confusing and alarming. Because the word carcinoma is used the natural assumption is that DCIS is invasive cancer. This is not correct. DCIS is a premalignant or precancerous condition of the breast. It is not invasive cancer but it does have the potential to change to invasive cancer if left in the breast. The main difference betweeen invasive cancer and precancer is that invasive cancer has the ability to invade into blood or lymph vessels and spread through out the body. Precancer or DCIS is not able to do this as the cells are contained within the duct walls ( see diagram ).
DCIS is graded by the pathologist into either high, intermediate or low grade. It is thought that high grade DCIS definitely becomes invasive in the time frame of a few years while low grade DCIS probably becomes cancerous but over a longer time period - 10-20 years. The intermediate grade DCIS has activity lying between high and low grade.3.Indeterminant Calcifications
Sometimes the calcification pattern is unclear and the calcifications are called indeterminant . To determine the nature of these microcalcifications, there are two options available.
* The microcalcifications can be biopsied either surgically or by stereotactic core biopsy .
*Alternatively a 6 month repeat mammogram can be done. The absence of any change over this time interval would suggest that the calcifications are a result of a benign process. Because the process of precancerous cells turning invasive takes years, reviewing the area through a 6 month mammogram is not felt to jeopardise the situation.
4. Benign Calcifications
The major group of calcifications seen on mammogram belongs in this group.Link to St Marks Breast Centre Online