Diagnosis

Tests and procedures used to diagnose melanoma include:

• Physical exam. Your doctor will ask questions about your health history and examine your skin to look for signs that may indicate melanoma.

• Removing a sample of tissue for testing (biopsy). To determine whether a suspicious skin lesion is melanoma, your doctor may recommend removing a sample of skin for testing. The sample is sent to a lab for examination.

  What type of biopsy procedure your doctor recommends will depend on your particular situation. Most often doctors recommend removing the entire growth when possible. One common technique, the punch biopsy, is done with a circular blade that's pressed into the skin around the suspicious mole. Another technique, called an excisional biopsy, uses a scalpel to cut away the entire mole and a small margin of healthy tissue around it.

Determining the extent of the melanoma

If you receive a diagnosis of melanoma, the next step is to determine the extent (stage) of the cancer. To assign a stage to your melanoma, your doctor will:

• Determine the thickness. The thickness of a melanoma is determined by carefully examining the melanoma under a microscope and measuring it with a special tool. The thickness of a melanoma helps doctors decide on a treatment plan. In general, the thicker the tumor, the more serious the disease.

  Thinner melanomas may only require surgery to remove the cancer and some normal tissue around it. If the melanoma is thicker, your doctor may recommend additional tests to see if the cancer has spread before determining your treatment options.

• See if the melanoma has spread to the lymph nodes. If there's a risk that the cancer has spread to the lymph nodes, your doctor may recommend a procedure known as a sentinel node biopsy.

  During a sentinel node biopsy, a dye is injected in the area where your melanoma was removed. The dye flows to the nearby lymph nodes. The first lymph nodes to take up the dye are removed and tested for cancer cells. If these first lymph nodes (sentinel lymph nodes) are cancer-free, there's a good chance that the melanoma has not spread beyond the area where it was first discovered.

• Look for signs of cancer beyond the skin. For people with more-advanced melanomas, doctors may recommend imaging tests to look for signs that the cancer has spread to other areas of the body. Imaging tests may include X-rays, CT scans and positron emission tomography (PET) scans. These imaging tests generally aren't recommended for smaller melanomas with a lower risk of spreading beyond the skin.

Other factors may go into determining the risk that the cancer may spread (metastasize), including whether the skin over the area has formed an open sore (ulceration) and how many dividing cancer cells (mitoses) are found when looking under a microscope.

Melanoma is staged using the Roman numerals 0 through IV. At stage 0 and stage I, a melanoma is small and has a very successful treatment rate. But the higher the numeral, the lower the chances of a full recovery. By stage IV, the cancer has spread beyond your skin to other organs, such as your lungs or liver.