A benign tumor does not have the ability to spread to distant organs and therefore can be completely excised. As it grows, it pushes away breast tissue and usually has a clear boundary around it. The goal of surgery is to remove the tumour but none of the surrounding normal breast tissue.
Removing a malignant tumor is different. A malignant tumor has fine offshoots that grow in all directions. These resemble the tentacles of an octopus. This boundary is often difficult to determine but it is essential to completely remove a malignant tumor. To ensure that the tumor and all its possible extensions are excised, a wide margin of surrounding normal tissue has to be removed.
The excised tissue is then examined under a microscope to check that all the offshoots have been removed. The edge of the removed breast tissue specimen is called the ‘tumor free resection zone’ or ‘tumor-free margin’.
Before undertaking a surgical procedure to remove the tumor, the exact nature and extent of the tumor should be determined to help plan surgery and fully inform the patient. All the possible alternatives to treat the tumor should be explained.
The removal of a breast tumor depends on its nature . The difference between a benign lesion and a breast cancer can be determined by physical examination and imaging of the tumor by mammography and ultrasound.
Ultimately, in all patients, confirmation of the diagnosis should be obtained before surgery by removing a small portion of the tumor and sending it for microscopic examination.
This is mostly done by needle biopsy:
- With fine needle aspiration, cells that are aspirated can be examined under the microscope.
- The most accurate method of histological diagnosis is a cylindrical biopsy. This is harvested using a slightly larger needle. This enables a more detailed microscopic examination and therefore accurate diagnosis.
- A mammotome is a vacuum assisted breast biopsy device that uses X-ray, ultrasound or MRI to perform a small breast biopsy. A mammotome biopsy can be done under local anesthesia and removes only a small amount of healthy tissue.
If the tumor is detected early and is small, only the tumor itself and a limited rim of healthy tissue of the breast may need to be removed. This surgical procedure is called a tumorectomy (fig. 1).
figure 1a: status after biopsy (fresh scar around the areola) of a tumor recurrence after a wide tumorectomy in the lower-inner quadrant of the right breast. Shape and volume asymmetry are visible but not grossly disturbing.
figure 1b: status after tumorectomy in the upper-inner quadrant of the right breast. Shape and volume asymmetry are visible but not grossly disturbing.
Incisions can be made over the tumor or at more concealed locations like the edge of the areola or within the crease below the breast (figure 2). After removal of the tumor, it will be examined histologically.
Fig. 2: possible incisions in the breast depending on size and location of the tumor. It is very important to position the incisions within the limits of the bra-line (first drawing).
Using mammographic screening, which is supported by most European Countries, small tumors that cannot be felt from outside can be detected. These tumors are often not palpable and so their removal is performed by needle localisation. Pre-operatively, a wire is placed by a radiologist to identify the site of the tumor (fig. 3a). At surgery, the wire is traced and the tissue at the tip of the wire is excised. The tissue with wire in situ are then sent back to the radiologist, while the patient is kept under anesthesia. The radiologist takes an X-ray to confirm that the correct area has been removed (fig. 3b).
Figure 3a: mammogram with needle localization of a non palpable tumor.
Figure 3b: X-ray of the same tumor after resection of both the tumor and wire.
If the wire indicates that the tumor is in the center specimen, one can be certain that it has been removed with a sufficient tumor-free margin. If the tumor is however close to one edge of the specimen, some additional breast tissue can be removed (wider excision) while the patient remains asleep.
If, after tumorectomy, the aesthetic appearance of the breast is affected, breast reconstruction may be indicated. Today small defects can easily be corrected by simple lipofilling. The different methods of breast reconstruction are discussed in other areas of this website.
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