What You Should Know About Your Skin Cancer Biopsy?

Types of Biopsies and Procedures for Diagnosing Skin Cancer

Doctor examining woman with melanoma
What do you need to know about your skin cancer biopsy?. Getty Images / Peter Dazeley / Photographer's Choice

If you have a suspicious spot on your skin, your doctor may recommend a skin biopsy to check for skin cancer. What types of biopsy procedures may be done, and why are different procedures recommended for different lesions? Will it hurt? What information will your doctor receive from the pathologist and what will be the next steps?

Definition

A skin cancer biopsy is done to see if an abnormal spot on your skin could be cancer.

Skin cancer is a very common condition, affecting over a million people each year in the United States.

Types of Skin Cancer and Biopsies Used

There are three primary types of skin cancer, and these are treated differently with respect to the biopsy procedure your doctor will recommend.

  • Melanoma - Melanoma is the most serious form of skin cancer and responsible for the majority of deaths from the disease. Since the staging of melanoma (and ultimately choosing the best treatment and estimating the prognosis) depends on accurately establishing the depth of the tumor, the type of biopsy your doctor chooses will be one which preserves the tumor as accurately as possible.

    Squamous cell and basal cell carcinomas are considered "non-melanoma" skin cancers and rarely spread. Most biopsy procedures, unlike with melanomas, can be used to diagnose these cancers.

    Types of Skin Cancer Biopsies

    Before discussing the different types of biopsies it's important to talk about the importance of different techniques. All too often a person has a biopsy done, only to later learn that a different technique may have offered more information, which in turn could have provided more direction in choosing treatment options. If you are suspicious that your skin lesion could be a melanoma, you may want to see a doctor who has a lot of experience treating melanoma. (This melanoma picture gallery shows images of melanomas.)

    Will the Biopsy Hurt?

    Before a biopsy is performed your doctor will numb the skin, usually by injecting lidocaine throughout the area to be biopsied. For those who are very sensitive to pain, the area can first be numbed with topical lidocaine applied for 20 or 30 minutes prior to the injection of lidocaine. Following the biopsy you should have minimal pain.

    Shave Biopsy

    A shave biopsy is a fairly simple biopsy which is done in a way very similar to how you would shave your face or your legs, though deeper.

    It is the most commonly performed type of biopsy, but works best with lesions that are raised (elevated above the level of surrounding skin.) This type of biopsy removes the epidermal layer of the skin and the top part of the dermis. A shave biopsy should not be done if a melanoma is suspected (other biopsy techniques should be considered for pigmented lesions). It is often the preferable method of evaluating skin lesions on the foot, since it does not carry the risk of separating and bleeding after the procedure.

    After the biopsy is taken, the area in which the skin was removed can be cauterized to prevent bleeding with aluminum hydroxide solution, or silver nitrate (although this can stain the skin.) The area should be kept clean and moist for a week to minimize scarring.

    Punch Biopsy

    A punch biopsy is performed in a method similar to a paper punch or a cookie cutter, and removes a cylindrical section of tissue. Different size punch biopsy tools are available and your doctor will choose the size which is able to remove the best sample with the least amount of scarring. The area to be biopsied is chosen and the sample is obtained by rotating the tool.

    A punch biopsy an be used to take a sample of a suspicious lesion, and if it is small enough, may be used to remove the entire lesion. A punch biopsy takes a deeper sample than a shave biopsy, removing the epidermis, the dermis, and a small amount of the subcutaneous tissue (or subcutis.) The area is often closed with a suture. As with a shave biopsy, a different type of biopsy should be considered if a melanoma is suspected.

    Incisional and Excisional Biopsies

    Incisional and excisional biopsies are both performed with a surgical knife. The difference is that an excisional biopsy (recommended if a melanoma is suspected) is done to remove the whole lesion whereas and incisional biopsy removes just a portion to evaluate. An elliptical incision is often made in order to help with closing the incision after the tissue is removed.

    Importance of Choosing the Right Type

    As noted above, a shave biopsy or punch biopsy may be considered if a lesion is suspicious for a basal cell or squamous cell skin cancer, but an excisional biopsy (preferably a wide excisional biopsy) should be performed if a melanoma is suspected.

    Despite guidelines set forth by the American Academy of Dermatology, however, this practice is not followed closely. In a 2016 it was found that there were significant differences in following these guidelines among US dermatologists. Of melanomas in one study:

    • 35 percent were detected by shave biopsy
    • 11 percent were detected by punch biopsy
    • Of those melanomas appropriately biopsied with an excisional biopsy, 31 percent were removed with a narrow excision rather than the recommended wide excision

    While recent studies have not found the type of biopsy to make a significant difference in survival as had been thought in the past, an appropriate biopsy increases the accuracy of diagnosis and staging, which can, in turn, be used to select the best treatment options and estimate prognosis.

    The crux of these findings is that people need to be their own advocates in their medical care. Ask questions. Carefully select your providers. And don't hesitate to get a second opinion.

    Healing

    No matter which type of biopsy technique you have done, it is important to keep your incision or biopsy site clean. There is no way of preventing scarring when a biopsy is done, but you may be able to minimize scarring by keeping the area clean to avoid infections (which can increase scarring) and by avoiding stressing the area biopsied.

    Complications

    Complications are uncommon with a skin biopsy but may include bleeding and infection. If you have a bleeding disorder or are on any medications which increase bleeding, make sure to talk to your doctor. Keep in mind that some herbal supplements may increase bleeding as well.

    Pathology

    It usually takes several days before your doctor receives a pathology report from the lab. Ask your doctor when she expects to get the report and find out if she will be calling you with results or if you need to schedule a follow up appointment.

    Staging and Other Biopsy Techniques

    If your skin biopsy reveals a melanoma, further biopsies may be done to evaluate the lymph nodes in the area near the tumor. Learn more about the pros and cons of lymph node dissection with melanoma.

    Bottom Line on Your Biopsy for Skin Cancer

    If you are having a biopsy for an abnormal lesion on your skin you are probably feeling anxious. It doesn't help when people suggest that it may "only" be skin cancer. Any type of cancer is frightening if it belongs to you. Whether or not your results reveal a cancer, take a moment to learn about skin cancer prevention. While sun exposure is a risk factor for skin cancer, the tide is changing, and it appears that some sun exposure may actually be recommended. A lack of vitamin D related to a lack of sun exposure is a significant risk factor for over a dozen cancers, including melanoma. If you haven't had your vitamin D level checked, your doctor may be able to draw your level when you are in the clinic for your biopsy.

    Sources:

    Farber, A., and D. Rigel. A Comparison of Current Practice Patterns of US Dermatologists Versus Published Guidelines for the Biopsy, Initial Management, and Follow Up of Patients with Primary Cutaneous Melanoma. Journal of the American Academy of Dermatology. 2016. 75(6):1193-1197.

    Kasper, Dennis, Anthony Fauci, Stephen Hauser, Dan Longo, and J. Jameson. Harrison's Principles of Internal Medicine. New York: McGraw-Hill Education, 2015. Print.

    Madu, F., Wouters, M., and A. van Akkooi. Sentinel Node Biopsy in Melanoma: Current Controversies Addressed. European Journal of Surgical Oncology. 2016. 2016 Aug 24. (Epub ahead of print).

    U.S. National Library of Medicine. Skin Lesion Biopsy. Updated 12/02/14. https://medlineplus.gov/ency/article/003840.htm

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