Once a lump or other unusual occurrence in the breast is detected, doctors cut into the breast to take a sample of the affected tissue. Many lumps are the result of calcium build-up and are referred to as "benign," meaning they are not cancerous. If a malignancy is detected in the sample, more tests are required to determine if the cancer is invasive or presents some characteristics of more aggressive forms of breast cancer. It is at this point that more tests are required to find out the type of cancer is present.
Breast cancer labelled as "invasive" has spread beyond the original point of origin. Whether is was initially found in a milk duct or lobule in the breast, it has spread to other parts of the breast and threatens to spread further if not removed and eradicated. Once the cancer cells get into the bloodstream or the lymphatic system through the lymph nodes, it can pose a serious threat.
Once a cancer is found to be invasive, the doctors look to the tissue sample and grade the tumour based on a system that determines the level of treatment required to stop the spread of the disease. The grading system is from one to three, with three being the most invasive and likely to spread quickly through the body. The closer the cell resembles the original tissue, the lower the grade. Tumours also are tested for the presence of hormones. Those with higher levels of oestrogen can be treated with hormone blocking drugs to slow the progression.
Inflammatory breast cancer is one of the aggressive types of breast cancer that does not typically begin as a lump in the breast. Instead, a reddening and thickening of the breast tissue characterise the disease. Other symptoms include a sudden increase in breast size, an inverted nipple or engorged lymph nodes under the arms or in the neck. Inflammatory breast cancer is not detectable by a mammogram, which is why a physician should check out any change in the look or feel of the breast. Since the initial symptoms often go unrecognized, the disease has often progressed to other parts of the body before it is detected.
Another form of aggressive breast cancer is Paget's disease, which originates on and around the nipple. It is characterised by itchy, flaky redness similar to eczema. The wounds may begin leaking and become painful. Most often, Paget's disease is a symptom of invasive breast cancer. Sometimes a lump is present, but not always. Paget's disease is most often found in women over the age of 50 who have not had children and who have a family history of breast cancer. A biopsy is the best way to test if the skin is just dry or is a sign of aggressive breast cancer.
A rare form of aggressive breast cancer is called metaplastic breast cancer, or metaplastic carcinoma. The disease can start in the glands, but most often begins in the cells lining the breast. Metaplastic breast cancer is typically invasive and has travelled to other areas of the body by the time it is diagnosed. Symptoms may include new lumps in the breast, inverted or discoloured nipples or dimpling on the skin of breast that causes it to itch and swell. Treatment of this type of cancer depends on the stage of the disease and the individual's general health, but typically follows other breast cancer treatments.