A skin biopsy is a procedure in which a sample of skin tissue is removed, processed, and examined under a microscope. Skin biopsies are performed to diagnose a number of conditions. Biopsies are not meant to actually treat a skin condition. Biopsy of skin is most frequently done to diagnose a skin growth such as a mole, or a skin condition such as a rash. A skin biopsy can also be used to diagnose a cancer of the skin. A skin biopsy may be indicated when a mole or other marking on the skin has changed in its shape, color, or size.There are four main types of skin biopsies: shave biopsy, punch biopsy, excisional biopsy, and incisional biopsy. The choice of the different skin biopsies is dependent on the suspected diagnosis of the skin lesion by the pathologist. A punch biopsy is generally the most useful type of biopsy. It is speedy to accomplish, convenient, and only produces a small wound. It creates a full thickness sample of skin that allows the pathologist to get a good overview of the epidermis, dermis, and most of the time, the subcutis also. Biopsy skin treatment is usually given by an injection with a thin needle. The numbing medication can cause a burning sensation in the skin for a few seconds to avoid any pain and discomfort. It usually takes about one or two weeks to obtain the result from the pathology laboratory, but can sometimes take longer if special stains or second opinions are required.