Diagnosis

Diagnosing skin cancer

To diagnose skin cancer, your doctor may:

  • Examine your skin. Your doctor may look at your skin to determine whether your skin changes are likely to be skin cancer. Further testing may be needed to confirm that diagnosis.
  • Remove a sample of suspicious skin for testing (skin biopsy). Your doctor may remove the suspicious-looking skin for lab testing. A biopsy can determine whether you have skin cancer and, if so, what type of skin cancer you have.

Determining the extent of the skin cancer

If your doctor determines you have skin cancer, you may have additional tests to determine the extent (stage) of the skin cancer.

Because superficial skin cancers such as basal cell carcinoma rarely spread, a biopsy which removes the entire growth often is the only test needed to determine the cancer stage. But if you have a large squamous cell carcinoma, Merkel cell carcinoma or melanoma, your doctor may recommend further tests to determine the extent of the cancer.

Additional tests might include imaging tests to examine the nearby lymph nodes for signs of cancer or a procedure to remove a nearby lymph node and test it for signs of cancer (sentinel lymph node biopsy).

Doctors use the Roman numerals I through IV to indicate a cancer's stage. Stage I cancers are small and limited to the area where they began. Stage IV indicates advanced cancer that has spread to other areas of the body.

The skin cancer's stage helps determine which treatment options will be most effective.

Treatment

Your treatment options for skin cancer and the precancerous skin lesions known as actinic keratoses will vary, depending on the size, type, depth and location of the lesions. Small skin cancers limited to the surface of the skin may not require treatment beyond an initial skin biopsy that removes the entire growth.

If additional treatment is needed, options may include:

  • Freezing. Your doctor may destroy actinic keratoses and some small, early skin cancers by freezing them with liquid nitrogen (cryosurgery). The dead tissue sloughs off when it thaws.
  • Excisional surgery. This type of treatment may be appropriate for any type of skin cancer. Your doctor cuts out (excises) the cancerous tissue and a surrounding margin of healthy skin. A wide excision — removing extra normal skin around the tumor — may be recommended in some cases.
  • Mohs surgery. This procedure is for larger, recurring or difficult-to-treat skin cancers, which may include both basal and squamous cell carcinomas. It's often used in areas where it's necessary to conserve as much skin as possible, such as on the nose.

    During Mohs surgery, your doctor removes the skin growth layer by layer, examining each layer under the microscope, until no abnormal cells remain. This procedure allows cancerous cells to be removed without taking an excessive amount of surrounding healthy skin.

  • Curettage and electrodesiccation or cryotherapy. After removing most of a growth, your doctor scrapes away layers of cancer cells using a device with a circular blade (curet). An electric needle destroys any remaining cancer cells. In a variation of this procedure, liquid nitrogen can be used to freeze the base and edges of the treated area.

    These simple, quick procedures may be used to treat basal cell cancers or thin squamous cell cancers.

  • Radiation therapy. Radiation therapy uses high-powered energy beams, such as X-rays, to kill cancer cells. Radiation therapy may be an option when cancer can't be completely removed during surgery.
  • Chemotherapy. In chemotherapy, drugs are used to kill cancer cells. For cancers limited to the top layer of skin, creams or lotions containing anti-cancer agents may be applied directly to the skin. Systemic chemotherapy can be used to treat skin cancers that have spread to other parts of the body.
  • Photodynamic therapy. This treatment destroys skin cancer cells with a combination of laser light and drugs that makes cancer cells sensitive to light.
  • Biological therapy. Biological therapy uses your body's immune system to kill cancer cells.

Clinical trials

Explore Mayo Clinic studies testing new treatments, interventions and tests as a means to prevent, detect, treat or manage this disease.

Preparing for your appointment

Make an appointment with your family doctor or a general practitioner if you notice any unusual skin changes that worry you. In some cases, you may be referred to a doctor who specializes in skin diseases and conditions (dermatologist).

Because appointments can be brief, and because there's often a lot of ground to cover, it's a good idea to be well-prepared. Here's some information to help you get ready, and know what to expect from your doctor.

What you can do

  • Be aware of any pre-appointment restrictions. At the time you make the appointment, be sure to ask if there's anything you need to do in advance, such as restrict your diet.
  • Write down any symptoms you're experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment.
  • Write down key personal information, including any major stresses or recent life changes.
  • Make a list of all medications, vitamins or supplements that you're taking.
  • Consider taking a family member or friend along. Sometimes it can be difficult to remember all the information provided during an appointment. Someone who accompanies you may remember something that you missed or forgot.
  • Write down questions to ask your doctor.

Your time with your doctor is limited, so preparing a list of questions can help you make the most of your time together. List your questions from most important to least important in case time runs out. For skin cancer, some basic questions to ask your doctor include:

  • Do I have skin cancer?
  • What type of skin cancer do I have?
  • Will I need additional tests?
  • How quickly does my type of skin cancer grow and spread?
  • What are my treatment options?
  • What are the potential risks of each treatment?
  • Will surgery leave a scar?
  • Do I have an increased risk of additional skin cancers?
  • How can I reduce my risk of additional skin cancers?
  • Should I have regular skin exams to check for additional skin cancers?
  • Should I see a specialist? What will that cost, and will my insurance cover it?
  • Is there a generic alternative to the medicine you're prescribing for me?
  • Are there brochures or other printed material that I can take with me? What websites do you recommend?
  • What will determine whether I should plan for a follow-up visit?

In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask other questions that occur to you.

What to expect from your doctor

Your doctor is likely to ask you a number of questions. Being ready to answer them may allow time to cover other points you want to address. Your doctor may ask:

  • When did you first notice your skin changes?
  • Have you noticed a skin lesion that has grown or changed?
  • Do you have a skin lesion that bleeds or itches?
  • How severe are your symptoms?

Skin cancer care at Mayo Clinic

June 13, 2018
References
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  3. Niederhuber JE, et al., eds. Melanoma. In: Abeloff's Clinical Oncology. 5th ed. Philadelphia, Pa.: Churchill Livingstone Elsevier; 2014. http://www.clinicalkey.com. Accessed April 22, 2015.
  4. Kaposi sarcoma treatment (PDQ). National Cancer Institute. http://www.cancer.gov/cancertopics/pdq/treatment/kaposis/HealthProfessional. Accessed April 22, 2015.