How Skin Cancer is Diagnosed

A person’s ability to recognize the signs of skin cancer and perform regular self-examinations are key to early detection. Any time skin cancer is suspected, the lesion should be examined by a dermatologist.

Dermatologists detect skin cancer through a visual examination of the skin and mucous membranes. If malignancy (cancer) is suspected, a biopsy will be performed. This involves numbing the area and removing the lesion, or part of it, for microscopic examination. A biopsy is the only way to definitely tell if skin cancer is present.

Since a skin biopsy is generally a quick and simple procedure, it is usually performed in a dermatologist’s office or outpatient setting. The type of biopsy performed depends on the type of skin cancer suspected, where on the body the tumor lies, and the tumor’s size. The different types of biopsy procedures used include:

* Excisional biopsy – The entire tumor along with a margin of tissue that is not a visible part of the tumor is removed. An excisional biopsy is the preferred method for removing lesions suspected to be melanoma.

* Incisional biopsy – A portion of the lesion is removed during an incisional biopsy, which is usually performed when the lesion is large. A scalpel; a hollow, circular scalpel-like instrument called a “punch” (punch biopsy); or a razor (shave biopsy) is used to remove the sample.

The removed sample is examined under a microscope to determine if cancer cells are present and if so which kind. If an excisional biopsy was performed, the physician examining the sample also should be able to determine how deeply the cancer has penetrated the skin.

Frequently, the removed sample is sent to a laboratory to be examined by a dermatopathologist, a medical doctor trained in both dermatology and pathology, who uses this expertise to microscopically examine tissue in order to diagnose skin conditions. Dermatopathologists provide expertise in diagnosing difficult cases.

In addition to removing the tumor or part of it, the dermatologist also will ask the patient some questions, which usually include when the lesion first appeared, symptoms, and the patient’s history of sun exposure.