Clinical aspects and pathology of melanoma

Abstract

The annual incidence of melanoma is continually increasing. Melanomas can easily be diagnosed because they are readily visible on the skin. The prognosis is excellent for melanoma when it is diagnosed in an early stage. The clinical diagnosis of melanomas is made by the simple A-B-C-D-E-rule. Clinically, we distinguish the following melanoma types by the order of frequency: the melanoma of the superficial spreading type (SSM), the melanoma with nodular type (NM), the lentigo maligna melanoma (LMM) and the acro-lentiginous melanoma (ALM). Other clinical subtypes of melanoma are congenital giant nevus and melanoma of the mucous membranes. With help of histogenesis, we can distinguish similar forms for melanoma of the SSM-type, melanoma of the NM-type, the lentigo maligna melanoma (LMM) and the melanoma of the ALM-type. In this case, it is preferable to use the terminology acanthotic-lentiginous melanoma since acro-lentiginous is the clinical expression and not a histopathological one. Further subtypes can be distinguished histopathologically such as the desmoplasic melanoma which has been recently described as melanoma from a dysplasic nevus as well as melanoma of the lichen cleanness type. Furthermore, due to histopathology other particular forms can be distinguished such as the melanoma of the nevus Spitz type and melanoma originating from a blue nevus. Most important for the histopathological report is the thickness of the melanoma in millimeters related to the Breslow index as well as the invasion level in the skin by the Clark classification since the melanoma thickness is the most important risk factor for the melanoma patient.