Diagnosing Melanoma

Are you wondering whether a mole or funny-looking spot of skin is melanoma? Melanomas usually look different from ordinary moles. The best way to find any suspicious moles on your body is to do a skin self-examination. Click here to print out a skin self-examination guide.

If you notice a mole that looks unusual or that has grown or changed color or shape in the last few months, you should tell your doctor. If your doctor also thinks the mole looks suspicious, he or she will refer you to a dermatologist (a physician who specializes in diseases of the skin). The dermatologist may do a biopsy. The dermatologist will remove a small piece of the mole or the entire mole. A pathologist (another special doctor) then looks at the sample under a microscope to check for cancer cells.

  • If the mole turns out to be melanoma, your dermatologist will need to find out more about the disease, based on:
  • how thick the tumor is
  • how far it may have spread

This process is called staging. Staging the melanoma is a very important step because the choice of treatment has a lot to do with the stage of the melanoma.

To find out how thick the melanoma is, the dermatologist or a surgeon will remove the entire tumor along with some skin around it (if this wasn't already done during diagnosis). At the same time, or in a later step, the surgeon may do a procedure called a sentinel lymph node (SLN) biopsy. This will help your doctor find out whether, and where, the melanoma has spread.

  • Other tests may also play a role in staging. These include:
  • blood tests
  • chest x-rays
  • CT (computed tomography)
  • MRI (magnetic resonance imaging)
  • PET scan (positron emission tomography scan)

After all traces of the tumor have been removed, you may see an oncologist, a cancer specialist. If the melanoma has spread to other areas or if there is a good chance the melanoma might come back, the oncologist may prescribe additional treatment.

Typical Steps in the Diagnosis of Melanoma

1

You find a suspicious mole or growth on your skin. You report it to your doctor.

2

The doctor refers you to a dermatologist, a skin specialist.

3

The dermatologist does an excisional biopsy and sends a sample of the growth to the lab. The pathologist at the lab checks the sample under a microscope to see if it is melanoma.

4

If it is melanoma, the dermatologist refers you to a surgeon for a sentinel lymph node or SLN biopsy. (Sometimes, the surgeon will remove the entire tumor and do the SLN biopsy at the same time, combining steps 3 and 4.)

5

If the dermatologist or surgeon has not yet removed the entire tumor and some surrounding skin, that happens next.

6

If tests show that melanoma has spread to nearby lymph nodes, the surgeon may remove those lymph nodes to help stop the cancer from spreading further.

7

If the melanoma has spread to the lymph nodes, you may have more tests including: blood tests, ultrasound, chest x-rays, or Magnetic Resonance Imaging (MRI) to check if the cancer has also spread to other organs.

8

After all surgery is completed, an oncologist (a doctor who specializes in cancer) may prescribe other treatments. These are called adjuvant treatments, and they may be in the form of immunotherapy, chemotherapy, or radiation therapy.

Glossary
Biopsy
Removal of a small piece of tumor tissue for diagnosis by microscopic examination.
Chemotherapy
The treatment of cancer (or other disease) with chemicals that are toxic to the cancer cells.
Dermatologist
A doctor who specializes in the diagnosis and treatment of skin problems.
Excisional Biopsy
A surgical procedure in which a tumor is removed and examined under a microscope to check for cancer cells.
Immunotherapy
A form of therapy that stimulates the immune system to kill or control cancer cells. Also called biochemical therapy or biotherapy.
Lymph Nodes
Glands that produce lymph and that filter out harmful agents (such as bacteria, viruses, and cancer cells).
Melanoma
A highly malignant type of skin cancer that arises in melanocytes, the cells that produce pigment. Melanoma usually begins in a mole.
Mole
A cluster of melanocytes and surrounding supportive tissue that usually appears as a tan, brown, or flesh-colored spot on the skin. Also called a nevus.
MRI
Magnetic Resonance Imaging. A radiology technique using magnetism, radio waves, and a computer to enhance internal images of the body.
Oncologist
A physician who specializes in treating cancer.
Pathologist
A doctor who identifies diseases by studying cells and tissues under a microscope.
PET Scan
A diagnostic test that produces images of the body by detecting radiation emitted from a radioactive substance that is administered to the patient.
Radiation Therapy
The treatment of cancer with high-energy X-rays. Also called radiotherapy.
SLN Biopsy
A surgical procedure in which lymph nodes that drain a tumor are identified and examined under a microscope to check for cancer cells.
Staging
A system for determining how far a tumor has spread from its point of origin.
Tumor
An abnormal mass of tissue that results from excessive cell division. Tumors perform no useful body function. They may either be benign (not cancerous) or malignant (cancerous).
Ultrasound
A procedure using sound waves that allows physicians and patients to get an inside view of soft tissues and body cavities, without using invasive techniques. It is most commonly used during pregnancy to view the fetus.