Diagnosis and Staging of Melanoma
Medical examinations and tests are used to determine if a suspicious area is melanoma skin cancer. In addition to a complete medical history, including family history, questions are asked about the marking on the skin, such as when you first noticed it, as well as if and how it has changed in size or appearance.
The suspected area, as well as the rest of your body is examined, noting the size, shape, color, texture, and if there is bleeding or scaling. A skin sample will probably be examined by a biopsy. The biopsy procedure chosen depends on the site and size of the affected area.
The different types of biopsies include the following:
- excisional or incisional biopsy
This type of biopsy is often used when a wider or deeper portion of the skin is needed. Using a scalpel (surgical knife), a full thickness of skin is removed for further examination, and the wound is sutured (with surgical thread).
When the entire tumor is removed, it is called excisional biopsy technique. If only a portion of the tumor is removed, it is called incisional biopsy technique. Excisional biopsy is often the method usually preferred when melanoma is suspected.
- fine needle aspiration (FNA) biopsy
This type of biopsy involves using a thin needle to remove very small pieces from a tumor. Local anesthetic is sometimes used to numb the area, but the test rarely causes much discomfort and leaves no scar.
FNA is not used for diagnosis of a suspicious mole, but may be used to biopsy large lymph nodes near a melanoma to see if the melanoma has metastasized (spread). A computed tomography scan (CT or CAT scan) - an x-ray procedure that produces cross-sectional images of the body - may be used to guide a needle into a tumor in an internal organ such as the lung or liver.
- punch biopsy
Punch biopsies involve taking a deeper sample of skin with a biopsy instrument that removes a short cylinder, or "apple core," of tissue. After a local anesthetic is administered, the instrument is rotated on the surface of the skin until it cuts through all the layers, including the dermis, epidermis, and the most superficial parts of the subcutis (fat).
- shave biopsy
This type of biopsy involves removing the top layers of skin by shaving it off. Shave biopsies are also performed with a local anesthetic.
- skin biopsy
Skin biopsies involve removing a sample of skin for examination under the microscope to determine if melanoma is present. The biopsy is performed under local anesthesia. The patient usually just feels a small needle stick and slight burning for about one minute, with a little pressure, but no pain.
Biopsies are obtained from the different skin layers:
- A shave biopsy generally involves obtaining tissue specimens from the thin outer layer of skin, called the epidermis.
- A punch biopsy generally involves obtaining tissue specimens from the epidermis. However, in some cases, a punch biopsy involves the dermis and subcutaneous tissue.
- An excisional biopsy generally involves obtaining tissue specimens from the deepest layer of skin, called the subcutaneous tissue.
When melanoma is found, more tests will be done to find out if the cancer cells have spread to other parts of the body. This is called staging, and is necessary before treatment for the cancer can begin.
The National Cancer Institute stages of melanoma are:
||Abnormal cells are found only in the outer layer of skin and have not invaded deeper tissue.
Cancer is found in the outer layer of the skin (epidermis) and/or the upper part of the inner layer of skin (dermis), but it has not spread to nearby lymph nodes. The tumor is less than 1.0 millimeters thick.
The tumor is less than 1.0 millimeters thick and ulcerated, or 1.0-2.0 millimeters and not ulcerated.
It has spread to the lower part of the inner layer of skin (dermis), but not into the tissue below the skin or into nearby lymph nodes. The tumor is 1.0-2.0 millimeters ulcerated or 2.0-4.0 millimeters and not ulcerated.
The tumor is 2.0-40 millimeters thick and ulcerated, or greater than 4.0 millimeters and not ulcerated.
The tumor is greater than 4.0 millimeters thick and ulcerated.
||The tumor has spread to the body tissue below the skin and to nearby lymph nodes.
||The tumor has spread to other organs, or to lymph nodes far away from the original tumor.
Always consult your physician for more information regarding the staging of melanoma.
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