Dermatoscopic prediction of melanoma thickness using latent trait analysisand likelihood ratios

Breslow thickness and Clark level can be used to determine surgical procedu res for cutaneous malignant melanoma and patient eligibility for experiment al adjuvant therapy, Efforts to predict the thickness of melanomas using de rmatoscopy have focused on differences between single dermatoscopic finding s. The aim of this study was to develop a method for preoperative identific ation of melanomas of greater than or equal to1 mm Breslow thickness using the entire range of dermatoscopic findings. Sixty-five melanomas were asses sed for the presence of 22 dermatoscopic features. Ten dermatoscopic featur es showed differences in thick and thin melanomas and were selected for fur ther analysis. A latent trait analysis construct implied that a progression in dermatoscopic features was associated with advancement of melanomas. Ea rly melanomas are characterized by a light brown colour, a pigment network and irregularity or heterogeneity. Gray - blue areas, white scar-like areas and an atypical vascular pattern gradually displace these features. Likeli hood ratios were determined for these 6 dermatoscopic findings and an algor ithm for calculating the probability of thick malignant melanoma was establ ished.