Cancer, inflammations, and abnormal growths on the skin are commonly diagnosed by a procedure called skin biopsy. This procedure involves the removal of a small skin tissue sample and its examination under microscope. Most skin biopsies involve minor surgery, and may require local anesthesia, although they usually don't require hospital stay.
There are several types of skin biopsies. A few examples are given below:
This involves the excision or removal of the whole tumor. Sometimes, healthy tissue around the tumor is also removed to prevent it from spreading. This type of biopsy usually leaves behind a small wound, so stitches and dressings may be needed to cover it up. Large excisional biopsies require skin grafts or skin flaps to speed up healing.
This involves the removal of a “bite” or “wedge” of tissue and only a portion of the tumor is removed, unlike the excisional method. Incisional biopsy is performed when the tumor or lesion is large or the affected area requires maximum preservation of tissue.
With this type of biopsy, the tissue sample is scooped out by a round needle similar to what a puncher does to a stack of paper. Punch biopsies are very tiny, so the wounds they create are usually left to heal without stitching. The common punch size used to diagnose most skin lesions are around 3.5mm to 4mm in diameter.