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To diagnose melanoma, we perform a careful skin inspection and a biopsy of suspicious skin lesions. Most of the time, the lesion is pigmented (tan, brown, black, or bluish in color) but sometimes may be "amelanotic" (flesh colored, pink or red in coloration).
The physical examination includes a dermoscopic evaluation, the use of a magnifying device to look closer at moles. We will examine the lesion of concern, as well as moles and skin on the rest of your body. We are specifically looking at the size, shape, color, texture and presence of bleeding or scaling.
We will also ask you about:
Your complete medical history, including family history
The mark on the skin:
When did you first notice it?
Has it changed in size or appearance? How?
Has it started bleeding or become painful or itchy?
If we suspect melanoma, we will most likely order a biopsy as well to confirm the diagnosis.
Diagnostic Tests for Melanoma
Learn more about the tests we use to determine if a mole is melanoma:
Skin Examination for Melanoma
A dermatologist checks the skin for moles, birthmarks, or other pigmented lesion that look abnormal in color, size, shape or texture. We will biopsy suspicious pigmented lesion so a pathologist can evaluate it.
Biopsy for Melanoma
We will perform a biopsy procedure using local anesthetic to remove as much of the suspicious mole or lesion as possible. A pathologist then looks at the tissue under a microscope to check for cancer cells. Because melanoma can be hard to diagnose, it is important that a pathologist trained in the evaluation of skin specimens, such as a dermatopathologist, performs the evaluation.
Types of biopsies used to diagnose melanoma include:
Skin biopsy diagram
Skin biopsy: Involves removing a sample of skin for examination under a microscope.
Excisional biopsy: Also called a wide local excision, an excisional biopsy involves surgical removal of a tumor and some normal tissue around it. The amount of normal tissue taken (also called the clinical margin) depends on the thickness of the tumor.
Punch biopsy: Involves taking a deeper sample of skin with a biopsy instrument that removes a short cylinder of tissue.
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.
We may order these advanced studies as part of your diagnosis:
SNaPshot genotyping: Much of current cancer therapy is targeted against specific genetic mutations in cancer cells and signaling pathways. This requires the rapid and accurate identification of genetic abnormalities that can predict a patient's response to a specific medication. Stanford dermatopathology uses a highly-sensitive clinical test to identify several of the most common genetic changes that cause melanoma. For some of these, targeted therapies are now available. We can perform this testing directly on the skin samples obtained for diagnosis. The mutations that we currently test include: BRAF V600E, BRAF V600M, NRAS Q61L, and NRAS Q61R.
Melanoma FISH (Fluorescent In Situ Hybridization) assay: Stanford dermatopathology uses a novel diagnostic assay (test) to detect genetic mutations in order to assist in the diagnosis of melanoma and to differentiate benign tumors from malignant ones. A four-probe fluorescent in situ hybridization assay may improve early classification of melanomas and has been demonstrated to aid diagnosis of melanoma cases that are difficult to diagnose.
Clinical trials are research studies that evaluate a new medical approach, device, drug, or other treatment. As a Stanford Health Care patient, you may have access to the latest, advanced clinical trials.
Open trials refer to studies currently accepting participants. Closed trials are not currently enrolling, but may open in the future.