A skin biopsy is the surgical removal of a sample of skin. Oftentimes, a visual examination is not sufficient to diagnose your condition appropriately. Dermatologists require a sample of the skin to undergo further evaluation and reveal clues invisible to the naked eye.
1. Biopsies sting but do not hurt a lot and heal quickly
Biopsies are usually performed after injecting a local anesthetic to numb the area. The anesthetic uses a very thin needle and is very quick and involves minimal pain. In some cases, after the biopsy, a suture or dressing may be applied to the site to repair the site. It heals within a few days or weeks. Applying petroleum jelly and using band-aid allows the wound to heal quickly with minimal to no scarring.
2. There are different types of biopsies
Your dermatologist will determine what type of biopsy is most appropriate given the appearance of your condition. Different types vary in their technique and depth. Some common examples include:
This is a common biopsy performed if the dermatologist determines the skin lesion (the part of the skin that has abnormal growth or appearance) is superficial, or in other words, at the surface level. An example is basal cell carcinoma.
A thin slice of skin is removed using a scalpel or a special biopsy razor blade. Stitches are not required. The resulting wound forms a small scab that generally heals in one to three weeks.
A modified shave biopsy may be performed when a greater depth of skin requires removal, such as a mole. It involves "scooping" the lesion. In some scoop biopsies, stitches may be required.
A punch biopsy involves removing a circular patch of skin producing a very small wound. It is quick to perform and provides a useful sample for the dermatologist. It tests the full thickness of the skin and allows the pathologist to obtain a cross-section of the epidermis, dermis, and sometimes the sub-cutis layers of the skin.
Punch biopsies are performed using disposable punches which are round and made with a stainless steel blade of varying diameters ranging from 2 to 6 mm. The 3 and 4 mm punches are the most common sizes used. The dermatologist holds the punch perpendicular to the numbed skin and rotates it to pierce the skin. The skin sample is removed using forceps and scissors. A suture may be used to close the wound or help control bleeding. If the wound is small, the dermatologist may not require the suture.
A skin curette may be used to scrape off a surface-level skin lesion, such as seborrheic keratosis. Some of the curette shavings may be sent to a pathologist for further evaluation.
3. Biopsy samples are evaluated by a board-certified pathologist
A board-certified dermato-pathologist takes each specimen obtained by the dermatologist and studies it on a slide under a microscope. They use their years of training and experience to provide a diagnosis or a set of possible diagnoses for our dermatologist to pinpoint.
4. Biopsies are medically necessary
Unless a shave biopsy is being performed to remove an unwanted mole or other cosmetic concern, biopsies are medically necessary to evaluate, and accurately diagnose your skin lesion. They help rule out cancer diagnoses or understand the specific root cause for a sudden inflammation. They are covered by your insurance. The specific amount owed by you is entirely dependent on your particular insurance plan, your deductible on the day of your visit, and your out of pocket expense for that year.
5. Biopsies conclusively narrow in on your condition
Without a biopsy, there runs the risk of potentially misdiagnosing or missing a serious disease such as skin cancer. It also helps determine the appropriate treatment. Generally, when a dermatologist performs a biopsy, they are further investigating two families of conditions - skin cancers and inflammatory conditions such as eczema and psoriasis. In some cases, the biopsy may be performed for a suspected skin infection.
For example, a suspicious mole may present signs of possible skin cancer, but a skin sample examined under a microscope in a laboratory will pinpoint whether it is truly a skin cancer or a benign growth. Furthermore, if it is skin cancer, the biopsy will identify if it is a squamous cell carcinoma or a melanoma or a rarer type. This conclusion will guide the dermatologist in determining the next course of action and the aggressiveness of the treatment.
In other cases, if the patient has an inflammatory condition, the biopsy will identify what type it is and aid the dermatologist in prescribing the right treatment with the right medications.
6. Biopsy results take approximately a week
Once the dermatologist takes the sample and sends it to a pathology lab for further evaluation, the biopsy results may take up to a week to arrive. Our dermatologist decides the next steps based on those results. You may be scheduled for a follow- up appointment to discuss results and the best course of action.