What is pathology of the breast?

When the breast is biopsied, the samples of tissue that were taken are sent to a pathologist who is a specialist in studying both these and the breast cells. The pathologist makes a report and diagnosis, which is sent back to the doctor. The doctor will then know how to manage the patient under their care. Breast cancer pathology results are important in deciding which treatments might work best for the individual and can also estimate the chance of the breast cancer recurring.

Understanding a breast pathology report

When tissue is removed from the breast, it is looked at under a microscope and a pathologist writes a report. The report will be written if a patient has a biopsy, breast-conserving surgery (the removal of cancer and a margin of normal breast tissue around it) or a mastectomy (removal of the breast tissue, including the nipple area). The pathology report contains clinical information, such as where the tissue was in the breast before it was removed. It contains the features of the breast tissue before it is looked at under a microscope. This section of the report is called the “macroscopic description” and includes information about the size, weight and appearance of the tissue. The next part of the report explains the features of cancer seen under a microscope.
 

What are the different types of breast cancer?

There are several types of breast cancer, which include:

• Primary breast cancer – this type of breast cancer has not spread beyond the breast or the lymph nodes under the arm. It can be invasive or non-invasive. Most breast cancers are invasive and have the potential to spread throughout the body.
• Invasive ductal breast cancer of no special type – most breast cancers are in this form. The term no special type is used because there are no features that are looked at under the microscope, which stand out.

Other types of breast cancer are known as a special type, as when looked at under a microscope they have certain features that characterise them. These include:

• ductal carcinoma in situ – an early type of non-invasive breast cancer.
• invasive lobular
• inflammatory
• Paget’s disease of the breast
• Tubular
• Cribriform
• Mucinous 
• Medullary
• Papillary
• Micropapillary
• malignant phyllodes
• metaplastic
   

How is breast cancer treated?

People with breast cancer often get more than one treatment. These may include:

• Surgery – where the doctor cuts out the cancer tissue.
• Chemotherapy – which kills or shrinks the cancer cells.
• Hormonal therapy – blocks cancer cells from getting the hormones they need to grow.
• Biological therapy
• Radiation therapy – uses high energy rays to kill the cancer cells.
   

Questions to ask the specialist team about the breast pathology report

The questions below may be useful to ask once receiving the breast pathology results:

• What type of breast cancer do I have?
• Is it invasive, non-invasive or both?
• What size the breast cancer?
• What grade is the breast cancer?
• Was the breast cancer tested for Ki67?
• Has cancer spread to the lymph nodes?