How is breast cancer diagnosed?

If an abnormality in the breast is detected, a diagnostic mammogram would be recommended in order to get clearer, more detailed images of the breast. Sometimes an additional test, such as an ultrasound (a detailed picture made by sound waves) would also be recommended to get more information.

Mammograms and ultrasounds can sometimes determine what the abnormality is. In certain cases, an MRI (magnetic resonance imaging) may also be required. If additional investigation is still needed, then a biopsy will be done.

What is a biopsy?

A biopsy is a procedure in which a small sample of tissue is removed from the breast.

There are three main types of biopsies:

Fine needle biopsy: Most often used for lumps that can be felt; a very fine needle is inserted into the lump to draw out a sample of cells.

Core needle biopsy: Most often used for a mass that can be felt by a doctor or that appears on a mammogram or ultrasound; the needle used is wider than the one used in a fine-needle biopsy.

Surgical biopsy: This involves removal of the entire lump through day surgery – (excisional biopsy or lumpectomy)

A pathologist, a doctor who specializes in examining tissue and diagnosing disease, examines the tissue collected in the biopsy under a microscope. The pathologist will be able to determine whether the tissue contains cancerous cells.

If you are going for a biopsy, be sure to find out who will be letting you know about your results and when you can expect them.

Links to more information

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Diagnosing Breast Cancer
Canadian Cancer Society

How is Breast Cancer Diagnosed?
Canadian Breast Cancer Foundation


For Women Facing a Breast Biopsy
American Cancer Society

Breast Biopsy
Mayo Foundation for Medical Education and Research

Having a Breast Biopsy: A Guide for Women and Their Families
Agency for Healthcare Research and Quality