In attempting to diagnose facial melanoma, dermatoscopic non-melanoma patterns may have a comparable diagnostic value, according to a recent study, making diagnosis of facial melanoma difficult. Scoring a lesion suspicious when no prevalent non-melanoma pattern is found resulted in a sensitivity of 88.5% and a specificity of 66.9% for the diagnosis of melanoma. Specificity was higher for solar lentigo (78.8%) and seborrheic keratosis (SK) (74.3%) and lower for actinic keratosis (61.4%) and lichenoid keratosis (25.6%). In this pilot study, facial lesions were collected retrospectively, resulting in a case set of 339 melanomas and 308 non-melanomas. Lesions were evaluated for the prevalence (>50% of lesional surface) of 7 dermatoscopic non-melanoma features: scales, white follicles, erythema/reticular vessels, reticular and/or curved lines/fingerprints, structureless brown color, sharp demarcation, and classic criteria of SK. Researchers found:
- Melanomas had a lower number of non-melanoma patterns.
- Evaluation of prevalent non-melanoma patterns can provide slightly lower sensitivity and higher specificity in detecting facial melanoma compared with already known malignant features.
Tschandl P, Gambardella A, Boespflug A, et al. Seven non-melanoma features to rule out facial melanoma. [Published online ahead of print August 1, 2017]. Acta Derm Venereol. doi:10.2340/00015555-2759.