Punch, Excision, & Incisional Biopsy

A skin biopsy is the removal of a sample of skin. It is usually undertaken using local anesthetic injection into the skin to numb the area. After the procedure, a suture or dressing may be applied to the site of the biopsy.

A skin biopsy may be deemed necessary as part of the diagnostic process. The additional information obtained from the biopsy can help identify diagnostic clues that are invisible to the naked eye.

Punch Biopsy
is generally the most useful type of biopsy. It is quick to perform, 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.

A disposable skin biopsy punch is used, which has a round stainless steel blade ranging from 2–6 mm in diameter. The 3 and 4 mm punches are the most common sizes used. The clinician holds the instrument perpendicular to the anaesthetized skin and rotates it to pierce the skin. Using a forceps and scissors the skin sample is subsequently removed.

A suture may be used to close a punch biopsy wound or help control bleeding. If the wound is small, it may heal adequately without it.

Shave Biopsy
may be used if the skin lesion is superficial, for example to confirm a suspected diagnosis of skin cancers

A tangential shave of skin is taken using a scalpel, special shave-biopsy instrument or razor blade. No stitches are required. The wound forms a scab that should heal in 1–3 weeks.

As a shave biopsy does not include the full thickness of the skin, the drawback of such a biopsy is that it may be difficult for a pathologist to rule out or identify invasive disease.

Skin Curette
may be used to scrape off a superficial skin lesion.Some of the curettings are sent for histopathology. These samples are not suitable for determining if a lesion has been completely removed.

Incisional Biopsies
refer to removal of a larger and generally deeper ellipse of skin, using a scalpel blade. Stitches are usually required after an incisional biopsy. This type of biopsy may be useful to provide a better overview for the pathologist, which can improve diagnostic accuracy. It can also be useful when deeper layers or tissue are believed to be involved in the disease process (eg, subcutaneous fat or medium-sized blood vessels).

Excision Biopsy
refers to complete removal of a skin lesion, such as a skin cancer in which a margin of surrounding skin is taken to improve chances of complete removal. Smaller lesions are most often removed using a scalpel blade as an ellipse, with primary closure using sutures.

“The best way to find yourself is to lose yourself in the service of others” – Gandhi.