What is a skin biopsy?
A skin biopsy is the removal of a piece of skin for the purpose of further examination in the laboratory using a microscope. Skin biopsies are performed to diagnose a number of conditions. Biopsies are not meant to actually treat a skin condition.
Why is a skin biopsy performed?
Skin biopsy 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.
What methods are used to obtain a skin biopsy?
Different techniques are used in different situations. Typically the biopsies are obtained after using local anesthetics to numb the area to be biopsied.
- A shave biopsy takes a thin slice off the top of the skin to be examined under the microscope.
- A punch biopsy takes a core (a small cylindrical fragment of tissue from the area of interest) and can be used to diagnose rashes and other conditions.
- Excisions are usually larger and deeper and are used to completely remove an abnormal area of skin such as a skin cancer. These are not technically biopsies since the goal of this procedure is to remove the whole lesion rather than to remove a small portion to make a diagnosis.
What happens to the skin sample after the biopsy is removed?
After the biopsy, the skin sample is fixed in special solution, and thin sections of the tissue are cut and placed on microscope slides. The slides are stained for examination by a doctor (usually a dermatologist or pathologist). Sometimes specialized stains are used to examine for antibodies, immune proteins, and other markers of certain diseases. Initial routine biopsy results can be obtained in 48 hours or less, while specialized staining techniques can require a longer time until final results are available.
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Medically reviewed by Norman Levine, MD; American Board of Dermatology
Alguire, Patrick C., M.D. Et al. "Skin biopsy techniques." UptoDate.com. Updated Nov. 2, 2015.