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Dermoscopy is useful in evaluating skin tumours, but its applicability also extends into the field of inflammatory skin disorders. Discoid lupus erythematosus (DLE) represents the most common subtype of cutaneous lupus erythematosus. While dermoscopy and videodermoscopy have been shown to aid the differentiation of scalp DLE from other causes of scarring alopecia, limited data exist concerning dermoscopic criteria of DLE in other locations, such as the face, trunk and extremities.To describe the dermoscopic criteria observed in a series of patients with DLE located on areas other than the scalp, and to correlate them to the underlying histopathological alterations.DLE lesions located on the face, trunk and extremities were dermoscopically and histopathologically examined. Selection of the dermoscopic variables included in the evaluation process was based on data in the available literature on DLE of the scalp and on our preliminary observations. Analysis of data was done with SPSS analysis software.Fifty-five lesions from 37 patients with DLE were included in the study. Perifollicular whitish halo, follicular keratotic plugs and telangiectasias were the most common dermoscopic criteria. Statistical analysis revealed excellent correlation between dermoscopic and histopathological findings. Notably, a time-related alteration of dermoscopic features was observed.The present study provides new insights into the dermoscopic variability of DLE located on the face, trunk and extremities.

Background Dermoscopy improves melanoma recognition, but most criteria were described in the context of superficial spreading melanoma. Objectives To test whether pigmented nodular melanoma could be recognized dermoscopically by the presence of a combination of blue and black colour within the lesion. Methods Dermoscopic images of histopathologically diagnosed pigmented nodular tumours with no (or only minimal) flat component were evaluated for the presence of standard melanoma criteria and for the presence of a new feature named blue-black (BB) colour. Sensitivity, specificity, positive predictive value and negative predictive value were calculated for standard criteria and BB feature in relation to the diagnosis of melanoma and to diagnosis of malignancy. Results Of 283 lesions, 160 were malignant, including 78 (27.6%) melanomas, and 123 were benign. The BB feature and the standard criteria had 78.2% and 43.6% sensitivity for melanoma, respectively, whereas a combined method based on the presence of either the BB feature or one (or more) of the standard criteria reached 84.6% sensitivity, with 80.5% specificity and 93.2% negative predictive value. Sensitivity values for malignant lesions were only 24.4%, 56.9% and 60% for standard criteria, BB feature and the combined method, respectively. However, the combined method gave 91.9% specificity and 90.6% positive predictive value for malignancy. Conclusions Using a method based on the BB feature or one of the standard melanoma criteria, only 9.4% of positive pigmented nodular lesions were found to be benign and only 6.8% of negative lesions were found to be melanoma histopathologically.