An Overview of Skin Cancer Biopsies

Learn which kind is best for basal cell, squamous cell, and melanoma

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 biopsy to check for skin cancer. This may bring to mind several questions. What types of skin cancer 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? Find out more details about the skin cancer biopsy process, below.

What Is a Skin Cancer Biopsy?

A skin cancer biopsy is done to see whether 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

There are three primary types of skin cancer, and what type of skin cancer that you have will determine which type of skin cancer biopsy is used.

  • Squamous cell skin cancer: Squamous cell carcinoma of the skin sometimes begins as an actinic keratosis, a scaly lesion with a red base that's related to sun exposure. This is the second most common type of skin cancer.
  • Basal cell carcinoma of the skin: Basal cell carcinoma is the most common form of skin cancer, responsible for around 80 percent of these tumors. The appearance of a basal cell carcinoma is often pearly and the tumor usually begins as a bump on the skin that eventually becomes depressed in the center (like a volcano.)
  • MelanomaMelanoma is the most serious form of skin cancer and it's responsible for the majority of deaths from the disease. Since the staging of melanoma (which affects the treatment plan and your prognosis) depends on accurately establishing the depth of the tumor, the type of skin cancer biopsy that your doctor chooses will be one that preserves the tumor as accurately as possible.

    Squamous cell and basal cell carcinomas are considered "non-melanoma" skin cancers and rarely spread. Most skin biopsy procedures can be used to diagnose these cancers, but the same is not true with melanoma.

    Types of Skin Cancer Biopsies

    • Shave biopsy: A shave biopsy is a fairly simple skin cancer biopsy that is very similar to how you would shave your face or your legs, though deeper. It is the most commonly performed type of biopsy, and it works best with lesions that are raised. 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 preferred 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 where 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 it removes a cylindrical section of tissue. Different sized punch biopsy tools are available and your doctor will choose the size that 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 can be used to take a sample of a suspicious lesion (or sometimes remove the entire lesion if it is small). 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. 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 an 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.

    Choosing the Right Biopsy

    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 the guidelines that have been set forth by the American Academy of Dermatology, these recommendations are not followed closely. In 2016, it was found that there were significant differences in how U.S. dermatologists followed these guidelines. For instance, when it came to melanomas in one study:

    • 35 percent were detected by shave biopsy
    • 11 percent were detected by punch biopsy
    • Of the melanomas that were 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 that the type of skin cancer biopsy makes a significant difference in survival as had been thought in the past, an appropriate biopsy increases the accuracy of the diagnosis and the cancer staging, which influences your treatment options and prognosis.

    The crux of these findings is that you need to be an informed advocate when it comes to your medical care. Ask questions, carefully select your providers, and don't hesitate to get a second opinion.

    Will a Biopsy Hurt?

    Before a skin cancer 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 that's applied for 20 or 30 minutes prior to the injection of lidocaine. Following the biopsy, you should have minimal pain.

    Healing

    No matter which type of skin cancer biopsy 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 that increase bleeding, 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. This determines whether or not the skin area is cancerous. Ask your doctor when he or she expects to get the report and find out whether he or she will be calling you with results or if you need to schedule a follow-up appointment.

    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.

    The Bottom Line

    If you are having a skin cancer 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 and it's normal to feel nervous. The good news is that when skin cancer is caught and treated early, it's curable, so regularly seeing a dermatologist for check-ups is always a good idea. 

    Whether or not your results reveal cancer, take a moment to learn about skin cancer prevention. Wearing a broad-spectrum sunscreen daily—especially when you have to be outdoors for a prolonged period of time—is important, along with staying indoors during the middle of the day, seeking out shade, and wearing sun-safe clothing such as rash guards, hats, and sunglasses. 

    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 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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