How Is Skin Cancer Diagnosed?

Doctors often can recognize skin cancer just by looking at it.

• Encourage your doctor to look for growths by doing a complete examination of the entire skin surface during a physical examination at least once a year; more often if you already have a past history of skin cancer.
• Many people detect skin cancer themselves while doing a regular skin self-examination. A biopsy, however, is the only certain way of identifying skin cancer, and determining the specific type of cancer. In a biopsy, the doctor removes cells or tissues for examination under a microscope. The examination usually is done by a dermatopathologist, a doctor who studies diseased tissue under a microscope.

Two types of biopsy are done for most skin cancers:

• An excisional biopsy excises, or cuts away, the entire visible growth. For small nonmelanoma skin cancer, an excisional biopsy may also be the only treatment necessary, whereas other cancers like malignant melanoma generally require additional removal of a wider margin of normal tissue around the site.
• An incisional biopsy, or core biopsy, removes only a sample of the growth. Further treatment is necessary if the microscopic examination reveals cancer cells. This is the most common type of biopsy.