Melanoma Diagnosis
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:
Advanced Molecular Studies
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.