Skin Cancer, Melanoma - Exams and Tests

Exams and Tests

Evaluation of a skin lesion

A physical exam of skin is used to evaluate the skin for melanoma. If melanoma is suspected, a skin biopsy will be done. For this, your health professional will remove a sample of skin tissue and send it to a pathologist to be examined under a microscope. If the biopsy shows melanoma, the pathologist will measure the thickness of the melanoma to determine how advanced the cancer is.³

Other techniques may include total-body photography to monitor for changes in any mole and to watch for new moles appearing in normal skin. A series of photographs of the suspicious lesions is taken as a baseline for comparison against later, follow-up photos.

Evaluation of lymph nodes

Testing the lymph nodes may not be necessary if the melanoma is less than 1 mm (0.04 in.) thick when measured with a microscope, because the risk of the cancer spreading may be low. You can expect more lab tests if your melanoma is large or thick.

If a melanoma is thicker than 1 mm (0.04 in.), your health professional will do a physical exam that includes checking the lymph nodes to see whether they are larger than normal. This may be followed by a lymph node biopsy to see whether the melanoma has spread to the lymph system.

A sentinel lymph node biopsy is a relatively new technique that may be used as an alternative to conventional lymph node biopsy. Like a conventional biopsy, sentinel lymph node biopsy is done to identify lymph nodes that may contain melanoma.

Evaluation for possible metastases (spread of cancer)

A complete medical history and physical exam are needed to determine whether the cancer has spread (metastasized) to other parts of the body. Imaging tests, including positron emission tomography (PET scan), computed tomography (CT scan) or magnetic resonance imaging (MRI), may be used to identify metastases in other parts of the body, such as the lungs, brain, liver, or other organs.

Early Detection

Skin self-exam is a good way to detect early skin changes that may indicate melanoma, because most primary melanomas are easily seen on the surface of the skin.³ A skin self-exam is used to identify suspicious growths that may be cancer or growths that may develop into skin cancer (precancers). Adults should examine their skin once every month. Look for any abnormal skin growth or any change in the color, shape, size, or appearance of a skin growth. Check for any area of injured skin (lesion) that does not heal. Have your spouse or someone such as a close friend help you monitor your skin, especially places that are hard to see such as your scalp and back.

There are other steps you can take to prevent skin cancer or detect it at an early stage.

• Be aware of the risk of skin cancer and the steps you can take to prevent it, including using sunscreen, wearing protective clothing, and staying out of the midday sun.
• Have your health professional examine any suspicious skin changes. Screening guidelines from the American Cancer Society and other expert groups recommend that adults older than 40 have their skin checked by a health professional at least once a year, as well as during any other health exam. This may lead to early treatment and prevent the possible spread of cancer. You may wish to begin screening earlier, especially if you have:
  • Familial atypical mole and melanoma (FAM-M) syndrome, which is an inherited tendency to develop melanoma. Examine your skin every month and be examined by a doctor every 4 to 6 months, preferably by the same doctor each time.
  • Increased occupational or recreational exposure to ultraviolet (UV) radiation.
  • Abnormal moles called atypical moles (dysplastic nevi). These moles are not cancerous, but their presence is a warning of an inherited tendency to develop melanoma.