Diagnosis and Staging of Melanoma
How is melanoma diagnosed?
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 mark 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 taken for a biopsy. The biopsy procedure used depends on the site and size of the affected area.
Types of biopsies
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 wedge 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 part of the tumor is removed, it is called incisional biopsy technique. Excisional biopsy is the method usually preferred when melanoma is suspected.
Fine needle aspiration (FNA) biopsy. This type of biopsy involves using a thin, hollow 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--or an ultrasound scan 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 deep 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). The biopsy sample is removed and the edges of the wound are then stitched together.
Shave biopsy. This type of biopsy involves removing the top layers of skin by shaving it off with a scalpel. Shave biopsies are also performed with a local anesthetic. This method may be used on moles if the chance if melanoma is very low, but these biopsies are not usually used if melanoma is suspected.
What is staging?
When melanoma is found, more tests might need to 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.
What are the stages for melanoma?
The American Joint Committee on Cancer stages of melanoma are:
Abnormal cells are found only in the outer layer of skin (epidermis) 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), is not ulcerated, has a low mitosis rate (the cells are dividing slowly), and it has not spread to nearby lymph nodes. The tumor is less than 1.0 millimeter thick.
The tumor is less than 1.0 millimeter thick and is ulcerated or has a higher mitotic rate.
It is 1.0 to 2.0 millimeters and not ulcerated. It is only in the skin, and not in nearby lymph nodes.
The melanoma is 1.0 to 2.0 millimeters and ulcerated
2.0 to 4.0 millimeters and not ulcerated. It is only in the skin, and not in nearby lymph nodes.
The melanoma is 2.0 to 4.0 millimeters thick and ulcerated.
Greater than 4.0 millimeters and not ulcerated. It is only in the skin, and not in nearby lymph nodes.
The tumor is greater than 4.0 millimeters thick and ulcerated, but it is only in the skin.
The melanoma is any thickness, not ulcerated, and has spread to one to three nearby lymph nodes, but the nodes are not swollen. There is no distant spread.
The melanoma is any thickness, not ulcerated, and has spread to one to three nearby lymph nodes, and the nodes are swollen. There is no distant spread.
The melanoma is any thickness, not ulcerated, and has spread to nearby skin or lymph channels, but it is not in the lymph nodes and there is no distant spread.
The tumor is ulcerated and has spread to one to three nearby lymph nodes which are swollen. There is no distant spread.
The melanoma is any thickness, is ulcerated, and has spread to one to three nearby lymph nodes or to nearby skin. The nodes are swollen, but there is no distant spread.
The melanoma is any thickness, is ulcerated, and has spread to nearby skin or lymph channels, but it is not in the lymph nodes and there is no distant spread.
The cancer may or may not be ulcerated and has spread to four or more lymph nodes, to lymph nodes that are clumped together, or to both nearby lymph nodes and lymph channels. The nodes are swollen but there is no distant spread.
The tumor has spread to other organs, or to skin or lymph nodes far away from the original tumor.
Always consult your doctor for more information regarding the staging of melanoma.