Using diagnostic tools for melanoma

Nearly one American dies from melanoma every hour. This was the dramatic start to the session, “Meeting the Challenges of Diagnosing Pigmented Lesions,” presented by Darrell S. Rigel, MD, MS, Clinical Professor of Dermatology, Icahn School of Medicine at Mount Sinai in New York, New York; and Laura Ferris, MD, PhD, associate professor of dermatology, University of Pittsburgh in Pennsylvania. The presenters shared the basics of melanoma, or what they called the ABCDE of the disease:
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Diameter (greater than ¼”)
Scalable (color and size changes)

These specific indicators can help the practitioner to correctly screen and diagnose this disorder: to this end, the presenters noted that genomics has also become a crucial part of the investigation of melanoma, helping in better detection of the disease. As cancer progression is genetically determined, prediagnostic genomic testing can be a powerful diagnostic tool.

Rigel and Ferris noted that the most available diagnostic tools rely on visual characteristics of the lesion, using whole body photography, dermoscopy, and confocal microscopy. In addition, some clinicians use other characteristics of lesions, such as impedance spectroscopy, the fast, non-destructive and easily automated technique for studying the electrical properties of materials, consisting of applying a sinusoidal voltage and measuring the response in running. Rigel and Ferris suggest using tools based on level of training: for example, a highly trained clinician might use dermoscopy and confocal microscopy, while a less trained person would use total body photography and spectroscopy.

Another diagnostic tool discussed was the pigmented lesion test (PLA), a noninvasive gene expression test that helps rule out melanoma and has the potential to reduce the need for surgical biopsies of atypical pigmented skin lesions.

The presenters also discussed preferentially expressed melanoma antigen (PRAME), immunohistochemical (IHC) staining, used to aid in the diagnosis of melanoma. In a study using PRAME with 178 melanomas (89.9% PRAME plus IHC), testing identified 100% superficial spread, 100% occurring in a congenital nevus, and 91.4% nodular, among other detections.

Learning about and using these various diagnostics and tests will only improve the diagnosis and, ultimately, the treatment of melanoma.


Rigel DS, Ferris L. Meeting the challenges of diagnosing pigmented lesions. Fall 2022 Clinical Dermatology Conference. October 21, 2022. Las Vegas, Nevada.