Accuracy of Dermoscopy
There are 3 groups of melanomas (1) those that can be easily diagnosed with the unaided eye (2) those that are missed by examination with the unaided eye but can be diagnosed by dermoscopy (3) those that can be diagnosed neither with the unaided eye nor dermoscopically.
There are several studies that have demonstrated an improvement in the diagnosis of pigmented skin lesions with dermoscopy compared with examination with the naked eye. There are however limitations of dermoscopy in the detection of early melanomas that lack specific dermoscopic criteria. The techniques success dependents on the appearance of classic dermoscopic features and is therefore limited in the diagnosis of these very early and mainly featureless melanomas. Dermoscopic algorithms such as pattern analysis, and the 7-point checklist can not reliably differentiate these early, featureless types of melanomas from melanocytic nevi.
These early melanomas can be recognized only by observing their dynamic evolution over time. The decision to excise can be made after follow-up with dermoscopy when these early lesions evolve characteristic dermosopic features.