Non-Melanoma Skin Biopsy

A biopsy is a procedure in which a doctor (generally a dermatologist) takes a sample of cells from the skin. A pathologist examines the tissue sample under a microscope and determines whether the cells are normal or cancerous.

We use the least disruptive biopsy procedure possible, minimizing discomfort while still obtaining enough cells to make a diagnosis.

  • For non-melanoma skin cancers confined to the top layers of the skin, the dermatology surgeon may do a standard excision. For this, the surgeon uses a scalpel to cut through the skin, remove a small amount of tissue, and then stitch the skin back together. This may remove the entire lesion if it is thin.
  • For non-melanoma skin cancers confined to the skin surface, surgeons will often do 1 of 3 other types of biopsy:
    • Saucerization. This uses a “deep shave” method to scoop out the skin tissue, which may remove the entire lesion. This does not require stitches.
    • Punch excision: The dermatologist pushes a circular device like a cookie cutter into the skin to remove the tissue. The skin is stitched back together.
    • Elliptical or fusiform excision: like a punch excision, this method takes a full thickness of the skin and requires stitches. It also takes a larger margin of skin around the lesion.

Skin cancers over a certain thickness (measured by the pathologist) are commonly staged with biopsy of the nearby (regional) lymph nodes, in a procedure called the sentinel lymph node biopsy. A lymphatic mapping study is done before the lymph node biopsy to learn exactly where your skin cancer might spread.

  • For a sentinel lymph node biopsy, doctors inject a safe radioactive dye around the skin site of the non-melanoma skin cancer. That dye travels along channels in the skin to the closest lymph node. A gamma probe (which acts like a Geiger counter) picks up radioactive spots. The lymph node (the size of an almond) can be removed and examined under a microscope for any cancer.

Lymph node biopsies are usually done when the initial skin biopsy shows that the skin cancer is 1 millimeter or more in thickness. Most patients diagnosed with skin cancer have thin skin cancers less than a millimeter that don’t need lymph node biopsies.

Pathology: Analyzing non-melanoma skin cancer biopsies

After you have a biopsy, the tissue sample is sent for review to our pathologists. A pathologist is a medical doctor who specializes in reviewing and evaluating lab tests, cells, and tissues to diagnose disease. Our pathologists analyze biopsy samples to determine whether the tissue is cancerous and, if so, what type of non-melanoma skin cancer it is.

For some skin cancers, a pathologist can examine the tissue immediately after the initial skin biopsy. For about 80 percent of skin cancer patients, the results show the melanoma was thin and limited to the top of the skin. If so, no further testing is needed. Treatment will still be needed.

Non-melanoma skin cancer tissue bank

Our doctors and researchers work to thoroughly understand the true diversity of non-melanoma skin cancers and identify the genetic abnormalities that can play a role in skin cancer formation. That’s why it’s critical that our doctors have access to tissue samples to plan for each patient’s care.

At Stanford, we store tissue samples, so we can use them for research, using the following process:

  1. Before we perform tissue sample, we will ask you if we may keep a small portion of the sample with our tissue bank. Our top priority is to confirm your diagnosis. Only a tiny portion of excess tissue is shared for research.
  2. If you approve, the excess tissue then goes to non-melanoma skin cancer research specialists. These doctors work with our clinicians (doctors involved in patient care) to identify new pathways of tumor formation and possible treatments.

Our non-melanoma skin cancer tissue bank provides our doctors and other researchers with a variety of different types of non-melanoma skin cancer cells to study. As we work on new methods and tools for diagnosing and treating skin cancer, our goal is to move these findings from the lab into patient care.

Stanford Health Library

For confidential help with your health care questions, contact the Stanford Health Library. Professional medical librarians and trained volunteers can help you access journals, books, e-books, databases, and videos to learn more about medical conditions, treatment options, and related issues. Visit us at:

  • 875 Blake Wilbur, Palo Alto: First floor near the cafe, 650-736-1960
  • South Bay Cancer Center: Third floor lobby, 408-353-0197

Email us your questions:

Current as of: 10/2019