Breast cancer may present with an abnormal physical exam, an abnormal mammogram, or both. A breast examination by a doctor can detect a suspicious mass, but it does not reveal enough information to make a definitive diagnosis of breast cancer. If you have a suspicious lump, your doctor may suggest one or more imaging tests, such as a mammogram or a sonogram. These tests might reveal that the lump is likely to be something harmless, such as a cyst, but they cannot definitively diagnose cancer.
If those tests do not rule out the possibility of a tumor, the next step is to have a biopsy, in which a sample of tissue is taken from the breast. The cells are then examined under a microscope by a pathologist, who can then determine if they are cancerous or not. Only by examining cells under a microscope can cancer be diagnosed.
If cancer is found, several other tests may be done to fully characterize its stage and type. This information, usually presented in a pathology report, is vital to developing the best treatment plan for each individual.
