DIAGNOSIS OF PIGMENTED LESIONS

Clinically numerous skin lesions have to be differentiated from malignant melanomas. Most important are the benign melanocytic lesions such as common melanocytic nevi, pigmented spindle cell nevi, Spitz nevi and blue nevi. From melanocytic lesions also pigmented non-melanocytic skin lesions have to be separated such as seborrhoic keratoses, pigmented basal cell carcinomas, verrucae vulgares, dermatofibromas, and vascular lesions such as hemangiomas, pyogenic granuloma, angiokeratoma or glomus tumors. Diagnostic accuracy in pigmented skin lesions can be dramatically improved by dermatoscopy, which is skin surface microscopy al 10x magnification, using a two step procedure. In the first step melanocytic and non-melanocytic lesions are differentiated by the melanocytic algorithm. In the second step the malignant potential of the melanocytic lesions is evaluated by the ABCD rule of dermatoscopy.