Do we need to rethink the diagnoses melanoma in situ and severely dysplastic naevus?

Many countries have seen a dramatic increase in the reported incidence of cutaneous melanoma in recent decades, largely driven by increased diagnoses of melanoma in situ and thin invasive melanoma. The incidence of thick and metastatic melanomas, and melanoma mortality have remained relatively stable. While aging populations could be causing some true increase in melanoma incidence, much of this increase may represent overdiagnosis: diagnosis of lesions that would never have caused harm if left undetected and untreated. If it occurs, melanoma overdiagnosis may result in potential psychological and physical harms to individuals, as well as significant cost to the healthcare system from procedures and long-term surveillance. The use of new diagnostic labels (e.g. “melanocytic neoplasm”2) and/or the recalibration of diagnostic thresholds for the diagnosis of melanoma in situ could reduce these harms. These strategies could also be applied to the diagnosis of severely dysplastic naevus, whereby the diagnostic label and apparent equivalence to melanoma in situ in the MPATH-Dx reporting schema ( with associated treatment recommendations) may also cause substantial anxiety for patients and clinicians.