Diagnosis of a suspicious mole or blemish may require a number of tests in order to diagnose whether it is a melanoma, a non-melanoma skin cancer, or another type of skin condition.
A thorough medical history is taken, followed by careful physical examination. Your doctor will pay close attention to signs including:
- Size, shape, color, texture of areas in question
- Symptoms such as scaling or bleeding
- Enlargement of lymph nodes, which could indicate spread of a melanoma
A dermatologist may perform a range of tests, depending on his or her findings.
Dermatoscopy (also known as dermoscopy, epiluminescence microscopy [ELM], or surface microscopy) uses light and a magnifying glass to better see spots on the skin.
If melanoma is suspected, biopsies may include the following:
- Skin biopsy: removal of a small sample of the skin
- Shave biopsy: removal of the top layer or layers of the skin with a small surgical blade
- Punch biopsy: removal of deeper layers of the skin using a tool that resembles a tiny cookie cutter
- Incisional biopsy: removal of a sliver or wedge of the full thickness of the skin. Incisional biopsies remove part of the tumor but not the whole tumor.
- Excisional biopsy: removal of the entire tumor, which is preferred if the lesion is suspected to be melanoma.
Biopsy of melanomas that may have spread
Biopsies of the lymph nodes or other areas of the body may be needed to determine if melanoma has spread, or in the event that other types of cancer are present, because different cancers are treated differently.
Fine needle aspiration biopsy is used to evaluate large lymph nodes near a melanoma to determine whether it has spread to these nodes.
Surgical (excisional) lymph node biopsy is the removal of tan enlarged lymph node to see if melanoma has spread.
Samples taken during biopsies are sent to the pathology laboratory, where they are examined under microscopes and tested.
Imaging tests may be performed to determine whether melanoma has spread to other parts of the body, to determine how well treatment may be working, or to check for recurrences.
- Chest x-ray may be used to check for spread to the lungs.
- CT scans can provide detailed images of soft tissues including lymph nodes and internal organs throughout the body.
- MRIs also give detailed images of the soft tissues of the body, and are particularly useful for the brain and spinal cord.
- PET scans (positron emission technology), which shows the metabolic activity of cells in the body, is useful in identifying advanced stages of melanoma.