Accuracy of dermoscopic criteria for the differential diagnosis between irritated seborrheic keratosis and squamous cell carcinoma.

BACKGROUND

Even with the addition of dermoscopy, a significant morphologic overlap exists between irritated seborrheic keratosis (ISK) and squamous cell carcinoma (SCC).

OBJECTIVE

The aim of this study was to investigate the dermoscopic criteria that could serve as potent predictors for the differential diagnosis between ISK and SCC.

METHODS

Dermoscopic images of histopathologically diagnosed ISKs and SCCs were evaluated by 3 independent investigators for the presence of predefined criteria.

RESULTS

A total of 104 SCCs and 61 ISKs were included. The main dermoscopic predictors of SCC were dotted vessels (odds ratio [OR], 10.4), branched linear vessels (OR, 5.30), white structureless areas (OR, 6.78), white circles surrounding follicles (OR, 23.45), a diffuse irregular (OR, 2.55) or peripheral (OR, 2.8) vessel arrangement, and a central scale arrangement (OR, 3.35). Dermoscopic predictors of ISK were hairpin vessels (OR, 0.38), a diffuse regular vessel arrangement (OR, 0.39 and OR, 0.36), and white halos surrounding vessels covering more than 10% of the lesion (OR, 0.29 and OR, 0.12).

LIMITATIONS

First, the retrospective design of the study; second, the differential diagnosis included in the study was restricted to ISK and SCC.

CONCLUSIONS

We confirmed the significant morphologic overlap between ISK and SCC, but we also identified potent predictors for the differential diagnosis between these 2 entities.