A skin biopsy is a medical procedure which involves taking a skin tissue sample, processing it, and then examining it under a powerful microscope. Different methods exist for performing this procedure depending on the location and size of the skin abnormality. Any part of your skin that shows some abnormality is called a lesion. After removal, the skin sample is placed in a suitable preservation fluid such as formaldehyde, or in a sterile container if any infection is suspected. After that, the tissue is processed and finally examined under a powerful microscope.
Why are skin biopsies performed?
A skin biopsy is necessary to help your doctor rule out skin diseases and conditions. This procedure can as well be used to remove lesions on your skin. In general, a skin biopsy can be used to diagnose and treat some skin diseases and conditions such as:
- Skin tags
- Actinic keratosis
- Fungal and bacterial skin infections
- Skin growths or suspicious moles
- Some stages and types of skin cancers such as melanoma, basal cell carcinoma, and squamous carcinoma
- Blistering skin diseases such as bullous pemphigoid
- Psoriasis and dermatitis, among other inflammatory skin disorders
Preparation for a skin biopsy
Before the doctor performs a skin biopsy, he or she may require you to provide some information such as whether you are:
- Allergic to any medications
- Taking any anti-inflammatory drugs such as prednisone, as these medications may change the nature of the tissue sample when viewed under a microscope
- Pregnant or might be
- Taking blood thinning medications such as warfarin, ibuprofen and aspirin, or have a history of bleeding problems
Actually, there are no special preparations needed for this type of biopsy. You may, however, be required to fill a consent form indicating that you understand the risks associated with the test and are ready for it. You may also talk to your doctor to know the reasons for his or her recommending a skin biopsy, how the procedure is performed, the risks associated with it, and what its results mean. To help you understand the importance of a skin biopsy clearly, you may be required to fill in a medical test information form.
How is a skin biopsy done?
Before the procedure, the place where the tissue sample is to be taken from is first cleaned with an alcohol wipe. A marker is then used to outline the boundaries of the area. For some types of biopsies, a surgical drape is used to help cover the biopsy area. Your doctor will wear a gown, a mask, and gloves. There are different procedures that may be performed to collect a skin sample for diagnosis. These procedures may depend on the location and the size of the skin lesion. After the skin sample is removed, it is placed in a suitable solution such as formaldehyde. In all types of procedures, the sample skin tissue is viewed under a powerful microscope. These methods include:
- Shave biopsy - In this procedure, a local anesthesia is injected at the biopsy site, after which a scalpel is used to cut off the skin growth. Stitches may not be needed for this procedure. Any bleeding is stanched using a chemical and by applying pressure. After the procedure, the site is covered with sterile dressing to prevent infection.
- Excision biopsy - In this procedure, a local anesthesia is injected to numb the cells and prevent pain. After that, a sharp and sterile scalpel is used to remove the entire lesion from your skin. Stitches are then used to close the resulting wound, and pressure is applied to the site of operation to help stop bleeding. Finally, the skin is covered with a sterile bandage. In case the excision is large, there will be a need for a skin graft.
- Punch biopsy - A local anesthesia is first injected, after which a special sharp tool called a punch is placed over the skin lesion. The tool, which looks like a cookie cutter, is then pushed down and slowly rotated to remove a circular piece of skin tissue. The circular skin sample is then lifted using a needle or forceps, and is cut from the rest of the skin at the base. Pressure is applied at the biopsy site until bleeding stops, or stitches are used to close the area in case a large sample is removed. The wound is finally covered with a sterile cloth or bandage to prevent infection and quicken the healing process.
After a skin biopsy
After the whole procedure, your doctor will give you some instructions on how to take care of your wound. You should always keep your wound clean and dry to facilitate quick healing. Your stitches will be taken out after 3 - 14 days after the skin biopsy, depending on the site and size of the biopsy. In case adhesive bandages are used to cover your wound, you should leave them to fall off on their own. This may take 7 to 14 days.
You should immediately call or visit your doctor in case you have:
- Chills or fever
- Increasing pain, swelling, and redness at the biopsy site
- Excessive drainage or bleeding
If there is too much bleeding, you should apply pressure and contact your doctor immediately.
Although skin biopsies are safe procedures, some complications could occur. These complications include:
- Allergic reactions to some medications such as topical antibiotics
- Bacterial or fungal infection
The results of a skin biopsy are available after 3 – 10 days. The results are said to be “normal” if the tissue sample revealed no abnormalities.
On the other hand, tissue is said to be abnormal if it contains:
- A fungal or bacterial infection
- Skin conditions such as psoriasis, lupus, and vasculitis
- Cancer cells such as squamous cell cancer, melanoma, and basal cell cancer
- Noncancerous (benign) growths or changes in the skin such as skin tags, keloids, warts, and cherry angiomas
A skin biopsy is a medical procedure wherein a sample of your skin tissue is removed in order to examine it for possible complications. To obtain perfectly safe results for a skin biopsy you should do provide your doctor complete and accurate information as required before the procedure as discussed above. There are few risks compared to the benefits of this medical procedure.