Incidence of cutaneous melanoma has increased globally mainly by the increased diagnoses of melanoma in situ and thin invasive melanoma. However, the incidence of thick and metastatic melanomas and their mortality have remained relatively stable. This increase in melanoma incidence may be due to the ageing population or overdiagnosis. This overdiagnosis may have potential psychological and physical harms to individuals, and a marked economic burden to the healthcare system from procedures and long-term surveillance.

Using new diagnostic labels (e.g. “melanocytic neoplasm”) and/or recalibrating the diagnostic thresholds for diagnosing melanoma in situ could address this concern. A similar approach can also be utilized in diagnosing severely dysplastic nevus. 

Literature research for supporting or rejecting a change to the diagnostic thresholds and/or terminology used for these low-risk melanocytic lesions was done and three lines of evidence were evaluated. 

1. Evidence on the natural history of these lesions was sparse since both melanoma in situ and severely dysplastic nevus are often managed with excision.
2. Evidence on the reliability of diagnostic criteria for the two types of lesions showed poor reproducibility for diagnoses of melanoma in situ and severely dysplastic nevus (MPATH-Dx class III).
3. Evidence of diagnostic drift in the diagnostic threshold over time suggest an assumed lowering of the diagnostic thresholds for melanoma and severely dysplastic nevus over time, causing expansion of the disease definition. 

Thus potent discussion, involving clinical and pathology communities, on the advantages and disadvantages of changing diagnostic thresholds and/or terminology to address potential overdiagnosis is needed.

Source- Semsarian CR, Ma T, Nickel B, Scolyer RA, Ferguson PM, Soyer HP, Parker L, Barratt A, Thompson JF, Bell KJL. Do we need to rethink the diagnoses melanoma in situ and severely dysplastic naevus?https://onlinelibrary.wiley.com/doi/epdf/10.1111/bjd.21010?