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This technique is effective for masses in all locations and generates a larger sample for histopathologic evaluation as compared to the needle core biopsy. The location of the incision should be carefully planned, as the biopsy incision will need to be removed during the definitive treatment. Care should be taken to avoid dissection and prevent hematoma or seroma formation as these may potentially seed tumor cells into the adjacent subcutaneous space. Although the junction of normal and abnormal tissue is often mentioned as the ideal place to obtain a biopsy sample, one should take care to avoid entering uninvolved tissues. The most important principle to consider is to obtain a representative sample of the mass. It is also important to obtain a sample that is deep enough and contains the actual tumor, rather than just the fibrous capsule surrounding the mass. Incisional biopsy has a higher potential for complications such as bleeding, swelling, and infection due to the increase in incision size and dissection.

Figure 1.4 Punch biopsy instrument, 8 mm in diameter.

Instrumentation includes a scalpel blade, local anesthetic, Metzenbaum scissors, forceps, suture, and hemostats. A Gelpi retractor or similar self‐retaining retractor aids in visualization if the mass is covered by skin. If the skin is intact and moveable over the mass, a single incision is made in the skin. Once the tissue layer containing the tumor is exposed, two incisions made in a parallel direction are started superficially and then meet at a deep location to form a wedge. The wedge is then grasped with forceps and removed. If the deep margin of the wedge is still attached, the Metzenbaum scissors can be used to sever the biopsy sample free of the parent tumor. The wedge site is then closed with a suture.