Melanoma is an aggressive cancer with an estimated 91,270 cases and 9,320 deaths in 2018. The lifetime risk of developing melanoma in the United States is 1 in 34 for men and 1 in 54 for women.
However, many melanomas are curable if they are detected early and diagnosed accurately. The 10-year survival rate for patients with stage I melanomas is 86-95%, compared with only 10-15% among patients with stage IV melanomas.
Melanoma can be difficult to diagnose, yet accurate and early diagnosis of melanocytic lesions is vital to improved patient outcomes. Histopathologic examination has long been the standard for melanoma diagnosis, and while it is adequate for most cases, evidence suggests that at least 15% of lesions are diagnostically challenging by histopathology. Even experienced dermatopathologists disagree in some cases, and, depending on the type of lesions evaluated, diagnostic discordance ranges from 15% to 38%. In these equivocal cases, patients often receive indeterminate or inaccurate diagnoses, leading to inappropriate treatment. For example, patients may receive unnecessary re-excisions, sentinel lymph node biopsies, and protracted clinical follow-up if a diagnostically challenging benign lesion is reported as indeterminate. Alternatively, a diagnostically challenging melanoma may be mistakenly diagnosed as a benign nevus, resulting in progression to late-stage melanoma.
Consequently, adjuncts to histopathology have been sought. Recently, Myriad myPath Melanoma, a 23-gene expression signature, has been developed as an objective and accurate method for differentiating malignant melanoma from benign nevi that overcomes some of these limitations.