[Classification, diagnosis and differential diagnosis of malignant melanoma]

Due to the recent increase of incidence of malignant melanoma and due to the significance of early detection for a definite cure from the disease, diagnosis and differential diagnosis of malignant melanoma are very important. At first glance the malignant potential of a pigmented mole can be evaluated by the macroscopical ABCD rule (Asymmetry, irregular Border, different Colors, and Diameter larger than 6 mm). In addition, also the history of the patient might be helpful. Thus a malignant melanoma should be considered when a patient reports a new rapidly growing pigmented lesion or a change in an existing mole in color, size, shape, and surface. Itching or burning should also arouse the suspicion of malignant change. Risk factors for the development of a malignant melanmoma are a high number of benign melanocytic nevi, large congenital melanocytic nevi, fair skin types with a tendency to sunburns and a malignant melanoma in the family of the patient. With dermatoscopy, which is skin surface microscopy at 10x magnification, the difficult macroscopical differential diagnosis is facilitated, because this technique opens a new dimension between macroscopy and microscopy.