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Interpreting Your Breast Cancer Pathology Report

    • image depicting negative and positive marginsIt is important to control the growth of the inflammatory breast cancer cells, and chemotherapy is often recommended first. Once chemotherapy is completed, the need for surgery and radiation will be determined.

      Tissue removed from the breast, lymph nodes or other parts of the body are sent to a laboratory to be viewed by a pathologist, a doctor who identifies diseases by studying cells and tissues under a microscope. The pathologist's written report of his or her findings is called a pathology report, which usually includes:

      • A detailed record of the specimens received and examined

      • A complete description of the appearance of the tissue cells, such as size, color and the presence of any visible abnormality

      • A report of all of the diagnostic findings after microscopic examination

      • A complete documentation of all of the studies performed on the tissue

      A copy of the pathology report is sent to your doctor and becomes part of your medical record. Below are some common terms routinely used in breast cancer pathology reports.

    • Final microscopic diagnosis

    • This section summarizes the pathologist's findings.

      • Infiltrating/invasive ductal breast carcinoma (IDC): cancer that started in the milk duct of the breast and has spread into surrounding breast tissue.

      • Infiltrating/invasive lobular breast carcinoma (ILC): cancer that started in the milk lobule of the breast and has spread into surrounding breast tissue.

      • Ductal carcinoma in situ (DCIS): early cancer cells growing in the lining of the milk duct in the breast.

      • Lobular carcinoma in situ (LCIS): early cancer cells growing in the milk lobule of the breast.

      • Grade: describes how much the cancer cells look like their normal cell counterparts. The Scarff-Bloom-Richardson scale is used to determine the grade.
        • Well-differentiated (grade 1) - the cells still have many of the features of normal cells.

        • Moderately differentiated (grade 2) - the cells have some of the features of normal cells.

        • Poorly differentiated (grade 3) - the cells have few of the features of normal cells.

      • Tumor size: size of the tumor measured under the microscope.

      • In situ component: If invasive cancer was found, there may be surrounding DCIS as well (see definition above), which will be noted in this section. If an extensive intraductal component (EIC) is noted, it means that the invasive cancer contains at least 25% DCIS.

      • Necrosis: cells that have died. Necrosis is usually associated with a more aggressive DCIS.

      • Architectural pattern: the pattern of growth of the DCIS cells. Descriptions used include cribiform, comedo, solid, micropapillary and papillary.

      • Angiolymphatic invasion: cancer cells have entered the small blood vessels or lymphatic vessels in the breast.

      • Margins: the area of normal tissue around the tumor that is removed during surgery. Ideally there are no cancer cells at the margin (clear or negative margin), only a rim of normal tissue. The pathologist will measure the distance between the cancer and the edge of normal tissue. If cancer cells are detected at the edge of the tissue removed, it is called a positive margin, and more surgery may be required.

      • Calcification: notes whether calcium deposits were found in the tumor.

      • Biopsy site: if a prior biopsy has been done, it will be noted whether the biopsy site is seen in the sample.

      • Nipple: if the nipple was removed (with a mastectomy), it will be noted if cancer is present in the nipple.

      • Sentinel node biopsy: if a sentinel lymph node biopsy was done, the report will note the number of lymph nodes containing cancer cells (positive lymph nodes), the size of the lymph nodes, and the total number of lymph nodes removed with the sentinel lymph node biopsy.

      • Axillary lymph node dissection: if cancer cells were found in the sentinel lymph nodes, the report will note the number of additional lymph nodes removed, the number containing cancer cells (positive lymph nodes), and the size of the lymph nodes. If an axillary lymph node dissection was planned, the report will note the total number of lymph nodes removed, the number that had cancer and the size of the lymph nodes.

      • Extracapsular extension: if cancer cells were found in the lymph nodes, the report will note whether the cancer cells are completely inside the lymph node (absent) or whether they extended outside of the lymph node (present).

      • Pathologic tumor stage (AJCC): a scale used by pathologists to summarize features of the tumor (T), number of lymph nodes with cancer (N), and metastatic sites (M).

      • Comments: includes specific pathologic findings and clarifications of what was seen in the pathologic specimen.

    • Clinical history

    • This section contains information on why the surgery is needed.

    • Gross description

    • This section gives specific details on what was given to the pathologist at the surgery and what it looks like without a microscope.

    • Addendum

    • Additional pathology reports will be made for invasive or infiltrating cancers. These reports will contain the following information:

      • Estrogen and progesterone receptors: the tissue will be sent to an outside laboratory to be tested for estrogen and progesterone hormone receptors in the cancer cells. These receptors receive and interpret messages by the hormones. Both hormones stimulate the growth of normal breast cells and some breast cancer cells. The results are usually available two weeks after surgery. If hormone receptors are present, then any hormones circulating in the body may affect the cancer’s growth. The report will list the percentage of cancer cells that had hormone receptors. Any percentage over 5% is considered hormone receptor positive.

      • HER2 staining intensity: The tissue will be sent to an outside laboratory to be tested to see if the cancer cells contain an overactive gene called HER2. The gene may make the cancer grow faster. The result may be listed as absent, 1+, 2+ or 3+. The report may also contain a second type of HER2 testing called FISH testing, which will be reported as either positive or negative.

      More on Understanding Your Diagnosis
      What is a cell? How does a cell become cancer?
      Lobular carcinoma in situ
      Ductal carcinoma in situ
      Invasive or infiltrating lobular carcinoma
      Invasive or infiltrating ductal carcinoma
      Inflammatory breast cancer
      Staging in breast cancer