A pathologist is a physician who analyzes cells and tissues under a microscope to determine whether they are cancerous, pre-cancerous, or benign (non-cancerous). The pathologist’s report helps characterize specimens taken during breast biopsy or other surgical procedures and helps determine treatment. Usually, the pathology report is written in highly technical medical language that may be difficult for the patient to understand. This section deciphers the complex terminology that may appear on a pathology report of the breast.
Breast cell and tissue samples are usually analyzed by a pathologist after breast biopsy, lumpectomy,mastectomy, and lymph node removal to determine their characteristics and help dictate treatment. Specimens are usually prepared for examination in one of two ways:
- Histologic sections: Immediately after the cells or tissues are taken from the breast, the specimen is placed in a fluid called a fixative for several hours. The fixative, often formalin (a 10% solution of formaldehyde gas in buffered water), causes the proteins in the cells to become hard and "fixed." The fixed specimen is then placed in a machine that automatically removes all the water and replaces it with paraffin wax. Several hours later, a technologist will remove the specimen and place it in melted paraffin, allowing the specimen to solidify by chilling. The specimen sections are floated out in water and picked up on a glass slide. The paraffin is dissolved from the tissue on the slide. With a series of solvents, water is restored to the sections, and the sections are stained in a mixture of dyes, making it easier to distinguish between the different parts of cells. Specimens may also be frozen immediately after they are taken from the breast. This technique allows the pathologist to examine histologic sections within a few minutes, but the quality of the sections is not as good as those of the permanent section.
- Smear: If the specimen is a liquid or made up of mostly liquid as with a fine needle aspiration (FNA) biopsy, a smear analysis made be done. FNA is often used to drain and sample fluid from a cyst (accumulated packets of fluid). The specimen is smeared on a microscope slide and is either allowed to dry in air, is "fixed" by spraying or is immersed in a liquid. The fixed smears are then stained and examined under the microscope. Like the frozen section, smear specimens can be examined within a few minutes of the time the biopsy was obtained. This is especially useful in FNA procedures in which a radiologist is using ultrasound or CT scan to find the area to be biopsied. The pathologist may be present in the room with the radiologist while the procedure is being performed. The radiologist can make one pass with the needle and immediately give the specimen to the pathologist, who can determine within a few minutes whether a diagnostic specimen was, in fact, obtained. The procedure can be terminated at that point, sparing the patient repeated sticks with the needle.
