SummaryThe present CME article highlights fundamental aspects with respect to the histopathology of the most common skin tumors (epidermal, adnexal, melanocytic, and mesenchymal), their laboratory workup, as well as the importance of supplementary immunohistochemical and molecular studies. The information provided is meant to assist experienced clinicians in choosing the correct biopsy technique and in interpreting dermatopathology reports, and to provide dermatology residents with a better understanding of dermatopathology. Similar to inflammatory dermatoses, the diagnosis of skin tumors, too, requires the close cooperation between clinicians and dermatopathologists. The diagnostic quality and the resultant therapeutic approach can be significantly improved if this collaboration is based on the same dermatological understanding.